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Sample records for biopreservation

  1. Bacteriocinogenic LAB from cheeses - Application in biopreservation?

    OpenAIRE

    Favaro, Lorenzo; Barretto Penna, Ana Lucia [UNESP; Todorov, Svetoslav Dimitrov

    2015-01-01

    Over the last decade, there has been an explosion of basic and applied research on lactic acid bacteria bacteriocins, because of their potential as biopreservatives and inhibition of the growth of spoilage bacteria. Although bacteriocins can be produced during cheese production, their titers are much lower than those achieved in vitro fermentations under optimal physical and chemical conditions. Safety and technological traits of the bacteriocinogenic lactic acid bacteria (LAB) have to be con...

  2. Biopreservation of Fior di Latte cheese.

    Science.gov (United States)

    Angiolillo, L; Conte, A; Zambrini, A V; Del Nobile, M A

    2014-09-01

    In this study a new biopreservation system consisting of an active sodium alginate coating containing Lactobacillus reuteri applied to Fior di Latte cheese was studied. The final aim was to extend cheese shelf life by the in situ production of reuterin. Experimental trials were carried out with and without glycerol. How the fermentation time could improve the production of reuterin, enabling Fior di Latte shelf life, was also assessed. To this aim, the experimental analyses were conducted in 2 different trials, using 2 different production batches of samples. In the first one, Fior di Latte samples were dipped into the active sodium alginate solution prepared on the same day of their production, whereas in the second trial, samples were dipped into the active solution prepared 48h before their production to allow a proper fermentation of the inoculated microorganism. Microbiological and sensory quality indices were monitored to prove the effectiveness of biopreservation on product quality during storage. In the first trial, the combination of the probiotic microorganism with glycerol improved the microbial quality by 1 d compared with the same active solution without glycerol, whereas the 48-h-fermented active alginate solution (second trial) showed a further improved microbial quality. The application of an active coating enriched with L. reuteri and glycerol to Fior di Latte cheese is an optimal and innovative way to preserve the product and at the same time, with a combination of an optimal fermentation time, to prolong its microbial quality and thus its shelf life.

  3. 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...

  4. 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.

  5. Application of Bacillus sp. as a biopreservative for food preservation

    OpenAIRE

    S. Nath,; Chowdhury, S.

    2015-01-01

    Food preservation is enhancing shelf-life and food quality to eliminate food-related illness and product spoilage, especially by the use of food additives.The growing consumer demand for effective preservation of food without altering its nutritional quality and free of potential health risks andto find an attractive and alternative approach to chemical preservatives, have stimulated research in the field of biopreservation by the use of natural or controlled microbiota and/or the...

  6. Role Of Biopreservation In Improving Food Safety And Storage

    OpenAIRE

    Swarnadyuti Nath; Chowdhury, S.

    2014-01-01

    Biopreservation refers to the use of antagonistic microorganisms or their metabolic products to inhibit or destroy undesired microorganisms in foods to enhance food safety and extend shelf life. In order to achieve improved food safety and to harmonize consumer demands with the necessary safety standards, traditional means of controlling microbial spoilage and safety hazards in foods are being replaced by combinations of innovative technologies that include biological antimicrobial systems su...

  7. 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 ...

  8. Role Of Biopreservation In Improving Food Safety And Storage

    Directory of Open Access Journals (Sweden)

    Swarnadyuti Nath

    2014-01-01

    Full Text Available Biopreservation refers to the use of antagonistic microorganisms or their metabolic products to inhibit or destroy undesired microorganisms in foods to enhance food safety and extend shelf life. In order to achieve improved food safety and to harmonize consumer demands with the necessary safety standards, traditional means of controlling microbial spoilage and safety hazards in foods are being replaced by combinations of innovative technologies that include biological antimicrobial systems such as lactic acid bacteria (LAB and/or their metabolites. Bacillus spp. have an antimicrobial action against Gram positive and Gram negative bacteria, as well as fungi, can therefore be used as a potential biopreservative in food processing due to its wide antimicrobial spectra. Bacteriocins are peptides or complex proteins biologically active with antimicrobial action against other bacteria, principally closely related species. Bacteriocins produced by lactic acid bacteria (LAB have received particular attention in recent years due to their potential application in food industry as natural preservatives. Bacteriocin production in Bacillus spp. has been studied over the past few decades which include Subtilin from B. subtilis, Megacin from B. megaterium and Thermacin from B. stearothermophilus. Bio-preservation may be effectively used in combination with other preservative factors (called hurdles to inhibit microbial growth and achieve food safety. Using an adequate mix of hurdles is not only economically attractive; it also serves to improve microbial stability and safety, as well as the sensory and nutritional qualities of a food.

  9. Application of Bacillus sp. as a biopreservative for food preservation

    Directory of Open Access Journals (Sweden)

    S. Nath,

    2015-04-01

    Full Text Available Food preservation is enhancing shelf-life and food quality to eliminate food-related illness and product spoilage, especially by the use of food additives.The growing consumer demand for effective preservation of food without altering its nutritional quality and free of potential health risks andto find an attractive and alternative approach to chemical preservatives, have stimulated research in the field of biopreservation by the use of natural or controlled microbiota and/or their antimicrobial compounds including very recent innovation: Bacillus sp., the ubiquitous, Gram positive bacteria, producing inhibitory substances like cyclic peptides and bacteriocins, with a broad antimicrobial spectrum and a history of safe use in food. Bacillus spores are also being used extensively as probiotic food supplements where they are used in human as dietary supplements and in feed for livestock and aquaculture as growth promoters.A novel concept multi-target food preservation has emerged in relation to hurdle technology stating the microbial safety, stability, sensorial and nutritional qualities of foods are based on the application of combined preservative factors (called hurdles including Bacillus sp. that microorganisms present in the food are unable to overcome, thus leading to inhibition of microbial growth by disturbing their homeostasis and metabolic exhaustion and avoiding tress reaction by bacteria. Future exploration of the natural preservatives and/or their metabolites, in combination with advanced technologies could result in replacement of chemical preservatives, or could allow less severe processing (e.g. heat treatments, while still maintaining adequate microbiological safety and quality in foods.

  10. Trends in utilization of agro-industrial byproducts for production of bacteriocins and their biopreservative applications.

    Science.gov (United States)

    Bali, Vandana; Panesar, Parmjit S; Bera, Manab B

    2016-01-01

    Bacteriocins are proteinaceous, ribosomally synthesized bio-molecules having major roles in food preservation due to their antimicrobial action against food spoilage microorganisms. These have gained importance in the last decades because of increasing interest in natural products and their applications in the field of biopreservation, pharmaceutical, aquaculture, livestock, etc. Their production is quite expensive which includes the cost of synthetic media and downstream processing of which 30% of the total production cost relies on synthetic media and nutritional supplements used for growth of microorganisms. The low cost agro-industrial by-products, rich in nutritional supplements, can act as a good substitute for high valued synthetic media. This review provides comprehensive information on the use of cost effective, renewable agro-industrial by-products as substrates for the production of bacteriocins and their application in food as biopreservatives.

  11. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    OpenAIRE

    José Luis Parada; Carolina Ricoy Caron; Medeiros,Adriane Bianchi P.; Carlos Ricardo Soccol

    2007-01-01

    Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therap...

  12. Pichia anomala J121: a 30-year overnight near success biopreservation story.

    Science.gov (United States)

    Schnürer, Johan; Jonsson, Anders

    2011-01-01

    Thirty years ago, the ascomycetous yeast Pichia anomala strain J121 was isolated from moist wheat grain stored under conditions of restricted air access. Early observations indicated that an inverse relationship existed between mould and P. anomala colony forming units in grain. This yeast strain was later found to have strong antifungal properties in laboratory, pilot and farm studies with high-moisture wheat under malfunctioning airtight storage. P. anomala had the highest inhibitory activity of 60 yeast species evaluated against the mould Penicillium roqueforti. It also demonstrated strong inhibitory effects against certain Gram-negative bacteria. P. anomala J121 possesses a number of physiological characteristics, i.e. capacity to grow under low pH, low water activity and low oxygen tension and ability to use a wide range of carbon and nitrogen sources, enabling it to act as an efficient biopreservative agent. The biocontrol effect in grain was enhanced by addition of glucose, mainly through formation of the volatile antimicrobial ethyl acetate. Animal feeding trials with P. anomala J121 inoculated grains, fed to chickens and beef cattle, demonstrated that mould control observed in vitro in small scale laboratory experiments could be extended to large scale farm trials. In addition, no adverse effects on animal weight gain, feed conversion, health or behaviour were observed. We have now studied P. anomala J121 biology, ecology and grain preservation ability for 30 years. Over this period, more than 40 scientific publications and five PhD theses have been written on different aspects of this yeast strain, extending from fundamental research on metabolism, genetics and molecular biology, all the way to practical farm-scale level. In spite of the well documented biopreservative ability of the yeast, it has to date been very difficult to create the right constellation of technical, agricultural and biotechnical industries necessary to reach a commercial launch of a

  13. Investigation into the Potential of Bacteriocinogenic Lactobacillus plantarum BFE 5092 for Biopreservation of Raw Turkey Meat.

    Science.gov (United States)

    Cho, Gyu-Sung; Hanak, Alexander; Huch, Melanie; Holzapfel, Wilhelm H; Franz, Charles M A P

    2010-12-01

    The bacteriocin-producing Lactobacillus plantarum BFE 5092 was assessed for its potential as a protective culture in the biopreservation of aerobically stored turkey meat. This strain produces three bacteriocins, i.e. plantaricins EF, JK and N. The absolute expression of Lactobacillus plantarum BFE 5092 16S rRNA housekeeping gene, as well as l-ldh, plnEF and plnG genes as determined by quantitative, real-time-PCR, revealed that these genes were expressed to similar levels when the strain was grown at 8 and 30 °C in MRS broth. On turkey meat, Lactobacillus plantarum BFE 5092 did not grow but survived, as indicated by similar viable cell numbers during a 9-day storage period at 8 °C. When inoculated at 1 × 10(7) CFU/g on the turkey meat and subsequently stored at 10 °C, the culture did again not show good growth. Lactobacillus plantarum BFE 5092 could not inhibit the growth of naturally occurring listeriae or Gram-negative bacteria on the turkey meat at 10 °C, or that of Listeria monocytogenes when it was co-inoculated at a level of 1 × 10(5) CFU/g. Gene expression analyses showed that the bacteriocin genes were expressed on turkey meat stored at 10 °C. Moreover, the investigation into the absolute expression of the three plantaricin genes of Lactobacillus plantarum BFE 5092 in co-culture with Listeria monocytogenes on turkey meat by qRT-PCR showed that the plantaricin genes were indeed expressed during the low-temperature storage condition. The Lactobacillus plantarum BFE 5092 strain overall could not effectively inhibit L. monocytogenes and therefore it would not make a suitable protective culture for biopreservation of turkey meat stored aerobically at low temperature.

  14. 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.

  15. Strategies to increase the hygienic and economic value of fresh fish: Biopreservation using lactic acid bacteria of marine origin.

    Science.gov (United States)

    Gómez-Sala, Beatriz; Herranz, Carmen; Díaz-Freitas, Belén; Hernández, Pablo E; Sala, Ana; Cintas, Luis M

    2016-04-16

    In this work we describe the development of a biopreservation strategy for fresh fish based on the use of bacteriocinogenic LAB of marine origin. For this purpose, two multibacteriocinogenic LAB strains, Lactobacillus curvatus BCS35 and Enterococcus faecium BNM58, previously isolated from fish and fish products were selected owing to their capability to inhibit the growth of several fish-spoilage and food-borne pathogenic bacteria. Two commercially important fish species were chosen, young hake (Merluccius merluccius) and megrim (Lepidorhombus boscii), and the specimens were acquired at the Marín (Pontevedra, Spain) retail fish market, after one night in the chilled hold of a near-shore fishing vessel. The biopreservation potential and the application strategies of these two LAB strains were first tested at a laboratory scale, where several batches of fresh fish were inoculated with: (i) the multibacteriocinogenic LAB culture(s) as protective culture(s); and/or (ii) their cell-free culture supernatant(s) as food ingredient(s), and (iii) the lyophilized bacteriocin preparation(s) as lyophilized food ingredient(s). All batches were stored in polystyrene boxes, permanently filled with ice at 0-2 °C, for 14 days. Microbiological analyses, as well as sensorial analyses, were carried out during the biopreservation trials. Subsequently, Lb. curvatus BCS35 was selected to up-scale the trials, and combinations of the three application methods were assayed. For this purpose, this strain was grown in a semi-industrial scale fermentor (150l) in modified MRS broth, and three batches of fresh fish were inoculated with the protective culture and/or food ingredient, and stored on ice in a chilled chamber at 0-2 °C at the Marín retail fish market for 14 days. Microbiological analyses were carried out during the storage period, showing that when Lb. curvatus BCS35 culture or the corresponding cell-free culture supernatant was used as protective culture or food ingredient

  16. Sonorensin: A new bacteriocin with potential of an anti-biofilm agent and a food biopreservative.

    Science.gov (United States)

    Chopra, Lipsy; Singh, Gurdeep; Kumar Jena, Kautilya; Sahoo, Debendra K

    2015-08-21

    The emergence of antibiotic resistant bacteria has led to exploration of alternative therapeutic agents such as ribosomally synthesized bacterial peptides known as bacteriocins. Biofilms, which are microbial communities that cause serious chronic infections, form environments that enhance antimicrobial resistance. Bacteria in biofilm can be upto thousand times more resistant to antibiotics than the same bacteria circulating in a planktonic state. In this study, sonorensin, predicted to belong to the heterocycloanthracin subfamily of bacteriocins, was found to be effectively killing active and non-multiplying cells of both Gram-positive and Gram-negative bacteria. Sonorensin showed marked inhibition activity against biofilm of Staphylococcus aureus. Fluorescence and electron microscopy suggested that growth inhibition occurred because of increased membrane permeability. Low density polyethylene film coated with sonorensin was found to effectively control the growth of food spoilage bacteria like Listeria monocytogenes and S. aureus. The biopreservative effect of sonorensin coated film showing growth inhibition of spoilage bacteria in chicken meat and tomato samples demonstrated the potential of sonorensin as an alternative to current antibiotics/ preservatives.

  17. Bacteriocinogenic lactic acid bacteria for the biopreservation of meat and meat products.

    Science.gov (United States)

    Hugas, M

    1998-01-01

    The consumer demands for less preserved foods and the development of new food systems to fulfil these demands, urges new hurdles for pathogen growth. The strategies for pathogen reduction are not selective for pathogenic microorganism and therefore the non-spoilage microorganisms may become also inactivated, from this situation a question of concern about a freer way for pathogen growth is arised. Biopreservation refers to the extended storage life and enhanced safety of foods using their natural or controlled microflora and (or) their antibacterial products. In meats, lactic acid bacteria (LAB) constitute a part of the initial microflora which develops easily after meat is processed. LAB growth in meat can cause microbial interference to spoilage and pathogenic bacteria through several mechanisms, specially bacteriocins. The paper deals with the description of meat-borne bacteriocins and their application in meat and meat products either to extend the shelf life or to inhibit meat pathogens. The application of bacteriocinogenic LAB together with new technological hurdles is discussed.

  18. Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

    Directory of Open Access Journals (Sweden)

    José Luis Parada

    2007-05-01

    Full Text Available Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS, useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therapeutic antibiotics. In this context, bacteriocins are indicated to prevent the growth of undesirable bacteria in a food-grade and more natural way, which is convenient for health and accepted by the community. According to their properties, structure, molecular weight (MW, and antimicrobial spectrum, bacteriocins are classified in three different groups: lantibiotics and non-lantibiotics of low MW, and those of higher MW. Several strategies for isolation and purification of bacteriocins from complex cultivation broths to final products were described. Biotechnological procedures including salting-out, solvent extraction, ultrafiltration, adsorption-desortion, ion-exchange, and size exclusion chromatography are among the most usual methods. Peptide structure-function studies of bacteriocins and bacterial genetic advances will help to understand the molecular basis of their specificity and mode of action. Nisin is a good example of commercial success, and a good perspective is open to continue the study and development of new bacteriocins and their biotechnological applications. These substances in appropriate concentrations may be used in veterinary medicine and as animal growth promoter instead usual antibiotics, as well as an additional hurdle factor for increasing the shelf life of minimal processed foods.

  19. 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.

  20. Identification of lactic acid bacteria with bio-preservative potential isolated from contaminated avian blood obtained at the slaughterhouse

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    MV Zbrun

    2013-01-01

    Full Text Available Blood is a common by-product of the meat industry, which has several potential applications in the animal feed industry. However, since blood is highly susceptible to microbial spoilage, blood and its fractions are often not suitable ingredients for the feed industry. Biopreservation appears as an alternative for the improvement of blood's quality towards its use as an ingredient in foodstuff. The objective of this work was to isolate and identify Lactic Acid Bacteria (LAB in avian blood obtained from industrial slaughterhouses and evaluate their antimicrobial activity. Ninety-six LAB were isolated from avian blood and genotyped. Eleven Amplified rDNA Restriction Analysis groups were identified. Between two and five different species were detected in each blood sample (31 strains in all blood samples which were selected to study antagonistic activity. Twenty-eight of them produced antimicrobial compounds such as organic acids, 11 strains produced hydrogen peroxide (H2O2 and two released bacteriocin-like compounds. The latter, identified as Lactobacillus salivarius (DSPV 027SA and Enterococcus faecalis (DSPV 008SA, inhibited the growth of Escherichia coli, Pseudomonas aeruginosa and some serotypes of Salmonella spp. These two LAB strains would be candidates for potential application as a blood biopreservation system. This biotechnological tool is cheaper than others sanitation techniques and could reduce the risk of pathogens transmission thought food chain.

  1. Antifungal sourdough lactic acid bacteria as biopreservation tool in quinoa and rice bread.

    Science.gov (United States)

    Axel, Claudia; Brosnan, Brid; Zannini, Emanuele; Furey, Ambrose; Coffey, Aidan; Arendt, Elke K

    2016-12-19

    The use of sourdough fermented with specific strains of antifungal lactic acid bacteria can reduce chemical preservatives in bakery products. The main objective of this study was to investigate the production of antifungal carboxylic acids after sourdough fermentation of quinoa and rice flour using the antifungal strains Lactobacillus reuteri R29 and Lactobacillus brevis R2Δ as bioprotective cultures and the non-antifungal L. brevis L1105 as a negative control strain. The impact of the fermentation substrate was evaluated in terms of metabolic activity, acidification pattern and quantity of antifungal carboxylic acids. These in situ produced compounds (n=20) were extracted from the sourdough using a QuEChERS method and detected by a new UHPLC-MS/MS chromatography. Furthermore, the sourdough was applied in situ using durability tests against environmental moulds to investigate the biopreservative potential to prolong the shelf life of bread. Organic acid production and TTA values were lowest in rice sourdough. The sourdough fermentation of the different flour substrates generated a complex and significantly different profile of carboxylic acids. Extracted quinoa sourdough detected the greatest number of carboxylic acids (n=11) at a much higher concentration than what was detected from rice sourdough (n=9). Comparing the lactic acid bacteria strains, L. reuteri R29 fermented sourdoughs contained generally higher concentrations of acetic and lactic acid but also the carboxylic acids. Among them, 3-phenyllactic acid and 2-hydroxyisocaproic acid were present at a significant concentration. This was correlated with the superior protein content of quinoa flour and its high protease activity. With the addition of L. reuteri R29 inoculated sourdough, the shelf life was extended by 2 days for quinoa (+100%) and rice bread (+67%) when compared to the non-acidified controls. The L. brevis R2Δ fermented sourdough bread reached a shelf life of 4 days for quinoa (+100%) and

  2. High hydrostatic pressure and biopreservation of dry-cured ham to meet the Food Safety Objectives for Listeria monocytogenes.

    Science.gov (United States)

    Hereu, Anna; Bover-Cid, Sara; Garriga, Margarita; Aymerich, Teresa

    2012-03-15

    This work aimed to evaluate the effect of nisin application (biopreservation) combined with high hydrostatic pressure processing (HHP) on the behavior of Listeria monocytogenes CTC1034 intentionally inoculated (at ca. 10(7)cells/g) onto the surface of ready-to-eat (RTE) sliced dry-cured ham. Two types of dry-cured ham, which had different water activities and fat contents were studied (a(w) of 0.92 and 14.25% fat and a(w) of 0.88 and 33.26% fat). Three batches were prepared for each type of product: (C) control, without nisin; (N) nisin directly applied (200 AU/cm(2)) and (F) nisin applied through active packaging, polyvinyl alcohol films with 200 AU/cm(2). Half of the samples were pressurized at 600 MPa for 5min. Counts of L. monocytogenes were periodically monitored throughout 60 days of storage at 8°C. The physico-chemical characteristics of the products enabled the survival of L. monocytogenes, but it was significantly reduced by the presence of nisin. The effect of biopreservation was greater when applied directly to the surface and in the product with lower water activity in comparison with the active packaging and the high water activity products, respectively. The immediate inactivation of L. monocytogenes by HHP ranged from 1.82 to 3.85 Log units, depending on the type of dry-cured ham. The lower the water activity, the less was the inactivation induced by HHP, both immediately and during storage. The reduction of L. monocytogenes immediately after HHP and during storage was more evident in batches with nisin applied directly to the surface of the product. The pathogen was not detected in some samples from day 5 of storage in the product with higher water activity. The effect of nisin applied through active packaging was lower than the direct application. The results of the present study indicated that HHP, as post-processing listericidal treatment, is more effective (both immediately and long term) than the use of nisin as an antimicrobial measure

  3. Discovery of novel biopreservation agents with inhibitory effects on growth of food-borne pathogens and their application to seafood products.

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    Chahad, Ouissal Bourouni; El Bour, Monia; Calo-Mata, Pilar; Boudabous, Abdellatif; Barros-Velàzquez, Jorge

    2012-01-01

    Selection of protective cultures is relevant in order to biopreserve and improve the functional safety of food products, mainly through inhibition of spoilage and/or pathogenic bacteria. Accordingly, the present study investigated potential applications of lactic acid bacteria (LAB) in the biopreservation of fish and shellfish products. For this purpose, a collection of 84 LAB strains isolated from sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata) was identified and characterized for their inhibitory activities against the most relevant seafood-spoilage and pathogenic bacteria potentially present in commercial products. The bioactive strains belonged to the genus Enterococcus and exhibited inhibition against Carnobacterium sp, Bacillus sp, Listeria monocytogenes, Aeromonas salmonicida, Aeromonas hydrophila and Vibrio anguillarum. Treatment of cell-free extracts of the LAB strains with proteases revealed the proteinaceous nature of the inhibition. Interestingly, the cell-free extracts containing bacteriocins remained 100% active after treatment up to 100 °C for 30 min or 121 °C for 15 min. Molecular analysis led to identification of the bacteriocins investigated, including enterocins A, B, L50 and P. All of these proteins demonstrated remarkable anti-Listeria activity and were found to be heat-resistant small class IIa bacteriocins. The results presented in this work open the way for potential applications of these LAB strains to the biopreservation of minimally-processed seafood products.

  4. Three Novel Lantibiotics, Ticins A1, A3, and A4, Have Extremely Stable Properties and Are Promising Food Biopreservatives.

    Science.gov (United States)

    Xin, Bingyue; Zheng, Jinshui; Xu, Ziya; Li, Congzhi; Ruan, Lifang; Peng, Donghai; Sun, Ming

    2015-10-01

    Lantibiotics are antimicrobial peptides with potential applications as the next generation of antimicrobials in the food industry and/or the pharmaceutical industry. Nisin has successfully been used as a food preservative for over 40 years, but its major drawback is its limited stability under neutral and alkaline pH conditions. To identify alternatives with better biochemical properties, we screened more than 100 strains of the Bacillus cereus group. Three novel lantibiotics, ticins A1 (4,062.98 Da), A3 (4,048.96 Da), and A4 (4,063.02 Da), which were highly thermostable (121°C for 30 min) and extremely pH tolerant (pH 2.0 to 9.0), were identified in Bacillus thuringiensis BMB3201. They all showed potent antimicrobial activities against all tested Gram-positive bacteria and greater activities than those of nisin A against Bacillus cereus and Listeria monocytogenes, two important foodborne pathogens. These three novel lantibiotics, with their extremely stable properties and potent antimicrobial activities, have the potential for use as biopreservatives.

  5. Application of bacteriocinogenic lactic acid bacteria in fermented vegetable food biopreservation%产细菌素乳酸菌在蔬菜发酵制品生物保鲜中的应用

    Institute of Scientific and Technical Information of China (English)

    饶瑜; 常伟; 唐洁; 李明元

    2013-01-01

    Biopreservation is the hot spot in the food preservation and safety research recently.Many strategies involving bacteriocin and bacteriocinogenic strains used in food biopreservation have been developed.This paper mainly focused on the state-of-the-art application of bacteriocinogenic lactic acid bacteria (LAB) as starter cultures,protective cultures or co-cultures to promote the microbial stability of fermented vegetable food products,as well as to control the survival and growth of spoilage/pathogen bacteria.%生物保鲜(biopreservation)是当今食品保藏和食品安全研究的热点.近年来,大量的研究致力于细菌素和产细菌素菌种在食品生物保鲜中的应用策略.本文主要介绍最新的产细菌素乳酸菌(LAB)在蔬菜发酵制品中的应用,通过将产细菌素乳酸菌作为发酵菌剂(starter culture)、保护菌剂(protective cuhure)或共培养菌剂(co-culture)运用到蔬菜的发酵制作中,以稳定蔬菜发酵过程中微生物体系,控制腐败和病原菌的存活和生长.

  6. Bio-preservative effect of the essential oil of the endemic Mentha piperita used alone and in combination with BacTN635 in stored minced beef meat.

    Science.gov (United States)

    Smaoui, Slim; Hsouna, Anis Ben; Lahmar, Aida; Ennouri, Karim; Mtibaa-Chakchouk, Ahlem; Sellem, Imen; Najah, Soumaya; Bouaziz, Mohamed; Mellouli, Lotfi

    2016-07-01

    The major compounds in Mentha piperita essential oil (EOMP) were menthol (33.59%) and iso-menthone (33%). The biopreservative effect of EOMP used alone at 0.25 or 0.5% and in combination with the semi-purified bacteriocin BacTN635 at 500 or 1000AU/g, on minced beef meat was evaluated by microbiological, physicochemical and sensory analyses during storage at 4°C for 21days. EOMP used alone limited the microbial deterioration of minced meat (P<0.05). Furthermore, the combination between EOMP and BacTN635 led to a decrease in TBARS values and slowed down the accumulation of MetMb. This combination was more efficient (P<0.05) against microflora proliferation and enhanced the sensory acceptability extending thus the shelf life of meat beef by approximately 7days. On the basis of these results, physicochemical and sensorial parameters could be used for constructing regression models to predict overall acceptability. Overall, the strongest preservative effect was achieved by using the combination of EOMP at 0.5% with BacTN535 at 1000AU/g.

  7. Poultry blood from slaughterhouses: development of a biopreservation system to improve microbiological quality prior to transforming blood into by-products.

    Science.gov (United States)

    Zbrun, M V; Frizzo, L S; Soto, L P; Rosmini, M R; Sequeira, G J; Astesana, D M; Blajman, J E; Rossler, E; Berisvil, A; Romero Scharpen, A; Signorini, M L

    2016-10-01

    The aim of this study was to investigate the use of indigenous lactic acid bacteria (LAB) with specific additives as a Biopreservation System (BS) for poultry blood during its storage in slaughterhouses. The BS consisted of two LAB (Enterococcus faecalis DSPV 008SA or Lactobacillus salivarius DSPV 032SA) with 4 additives (lactose 2 g/l, yeast extract 0.4 g/l, ammonium citrate 0.4 g/l and NaCl 1 g/l). After 24 h storage at 30ºC, lower counts of enterobacteria, coliforms, Pseudomonas spp. and Staphylococcus aureus were evident in blood treated with the BS than in untreated blood. The ability of LAB to prevent haemolysis was evident. A decrease in pH was associated with control of spoilage microorganisms but it needed to be regulated to prevent coagulation of proteins. On the basis of these results it is recommended to supplement blood with a BS to avoid undesirable changes during blood storage before processing.

  8. Biopreservation in modified atmosphere stored mungbean sprouts: the use of vegetable-associated bacteriocinogenic lactic acid bacteria to control the growth of Listeria monocytogenes.

    Science.gov (United States)

    Bennik, M H; van Overbeek, W; Smid, E J; Gorris, L G

    1999-03-01

    Two bacteriocinogenic strains of Pediococcus parvulus and one bacteriocinogenic Enterococcus mundtii strain were evaluated for their potential to control the growth of Listeria monocytogenes on refrigerated, modified atmosphere (MA) stored mungbean sprouts. These three strains, which were isolated from minimally-processed vegetables, were shown to grow in culture broth at 4, 8, 15 and 30 degrees C. However, only Ent. mundtii was capable of bacteriocin production at 4-8 degrees C. Examination of the growth of these strains on agar under 1.5% O2 in combination with 0, 5, 20 or 50% CO2 revealed significantly higher maximum specific growth rates for Ent. mundtii than for Pediococcus parvulus at CO2 concentrations below 20%, which are relevant for MA-storage of vegetables. Enterococcus mundtii was subsequently evaluated for its ability to control the growth of L. monocytogenes on vegetable agar and fresh mungbean sprouts under 1.5% O2/20% CO2/78.5% N2 at 8 degrees C. The growth of L. monocytogenes was inhibited by bacteriocinogenic Ent. mundtii on sterile vegetable-medium but not on fresh produce. However, mundticin, the bacteriocin produced by Ent. mundtii, was found to have potential as a biopreservative agent for MA-stored mungbean sprouts when used in a washing step or a coating procedure.

  9. New Antifungal Bacteriocin-Synthesizing Strains of Lactococcus lactis ssp. lactis as the Perspective Biopreservatives for Protection of Raw Smoked Sausages

    Directory of Open Access Journals (Sweden)

    L. G. Stoyanova

    2010-01-01

    Full Text Available Problem statement: Screening for the effective bacteriocin-synthesizing strains of Lactococcus lactis as the perspective biopreservatives was performed. We used a raw milk and dairy products from different climatic regions as well as from powerful drinks of mixed lactic acid and alcoholic fermentation: kurunga, kumiss and Iranian Dough, that were widely used by local population to prevent diseases. Approach: The special interest was paid to isolates of lactococci with antagonistic activity. According to their morphological, cultural, physiological, biochemical properties and sequence of 16S rRNA gene they were identified as Lactococcus lactis ssp. lactis. Only nine from the selected 94 strains expressed a broad spectrum of activity against Gram-positive and Gramnegative bacteria including pathogens (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella gallinarum, moulds (Aspergillus, Fusarium, Penicillium genera, as well as yeasts (Rhodotorula, Candida. Results: It reveals the unique biological properties for isolated natural strains of Lactococcus lactis species. Most effective new bacteriocin-synthesizing strains 194 and K-205 were isolated from raw cow milk and kurunga from Buryatia. These strains had high antibiotic activity up to 3600 and 2700 IU mL-1 as compared to nisin and up to 2500-1700 IU mL-1 as compared to fungicidal antibiotic nistatin. In our experiments we used raw smoked sausages that were infected with fungi. The identification of this infection showed the presence of Eurotium repens de Bary on the sausages. Treatment of the raw smoked sausages with cultural broth of L.lactis ssp. lactis 194 and K-205 inhibited growth of these microorganisms. After treatment the sausages had longer shelf-life and was in accordance with basal production data (Russian State Standard Specification 16131-86. Conclusion: The results of this study indicated that the treatment with

  10. Isolasi dan Identifikasi Bakteri Asam Laktat dari Cairan Rumen Sapi Bali sebagai Kandidat Biopreservatif ISOLATION AND IDENTIFICATION OF ACID LACTIC BACTERIA FROM BALI CATTLE’S GASTRIC FLUID AS A POTENTIAL CANDIDATE OF BIOPRESERVATIVE

    Directory of Open Access Journals (Sweden)

    I Wayan Suardana

    2007-12-01

    Full Text Available A study was conducted to isolate and identify of lactic acid bacteria originated from gastric fluid of bali cattle, and to determine their potential as the candidates of biopreservative. Lactic acid bacteria were isolated by culturing the gastric fluid of bali cattle in de Mann, Rogosa, Sharpe (MRS medium; screening the bacteria, and identification of bacteria species by Analytical Profile Index (API 50 CHL Kit. The results showed that, the new species of lactic acid bacteria were isolated and identified as Lactococcus lactis spp lactis 1 (SR21 isolate and Lactobacillus brevis 1 (SR54 isolate that have broad spectrum antimicrobial activities. It is clear from this study that a potential lactic acid bacteria producing antimicrobial agent can be isolated from the gastric fluid of bali cattle.

  11. Effect of inoculation of Carnobacterium divergens V41, a bio-preservative strain against Listeria monocytogenes risk, on the microbiological, chemical and sensory quality of cold-smoked salmon.

    Science.gov (United States)

    Brillet, Anne; Pilet, Marie-France; Prevost, Hervé; Cardinal, Mireille; Leroi, Françoise

    2005-10-25

    The aim of this study was to develop a bio-preservation strategy for cold-smoked salmon (CSS) by the use of lactic acid bacteria previously selected for their capability to inhibit the growth of Listeria monocytogenes in the product. The spoiling potential of three Carnobacterium strains (Carnobacterium divergens V41, Carnobacterium piscicola V1 and SF668) was tested in sterile CSS blocks inoculated by 10(4-5) CFU g(-)(1) and stored under vacuum for 9 days at 4 degrees C followed by 19 days at 8 degrees C. C. divergens V41 grew a little faster than the other strains and none of the three carnobacteria showed any adverse effect on quality of the product, i.e. no off-odour detected by a trained panel, no total volatile basic nitrogen (TVBN) production, no acidification and no biogenic amine except a slight production of tyramine. An application on commercial CSS was tested by spraying C. divergens V41 (10(4-5) CFU g(-1)) on slices of four batches freshly processed in different smoke-houses. Microbial, chemical and sensory characteristics were weekly compared to a control during 4 weeks of vacuum storage. When the natural microflora was initially weak (two batches10(4-5) CFU g(-1)), no effect on the microflora, TVBN and biogenic amine production, nor on the sensory characteristics was observed in presence of C. divergens V41. In conclusion, bio-preservation of CSS using lactic acid bacteria such as C. divergens V41 is a promising way to inhibit the growth of pathogenic bacteria such as L. monocytogenes with low effect on the quality of the product.

  12. Biopreservative in Foods: Nisin (E234

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    Başar Uymaz

    2015-12-01

    Full Text Available Fermentation is the oldest traditional method in order to protect against spoilage and pathogenic microorganisms. Thermal treatment, pH and water activity lowering and preservative addition other food preservation techniques that are commonly used. Although, as preservatives, many improved antibiotic and chemical agents have been gained, there are some other factors such as rapid resistance to antibiotics used in bacteria, in order to limit their use in food, to be found dimensions of threatening human health of the chemical protection and to cause allergic reactions. Recently, studies on bacteriocins that are produced by the safe bacteria, such as lactic acid bacteria, contain no toxic and adverse effects for human consumption have gained sudden intensity in accordance with the request against consumers in developing microbiologically safe and minimal processed food. There are some important effects using of bacteriocins accepted the new generation of antimicrobial agents as food preservatives such as extension of shelf life, reducing of the use of chemical preservatives and the economic loss caused degradation by microorganisms. Nisin, defined as GRAS (Generally Recognized as Safe by FDA and named the E234 code 'Nisin-protective' or 'natural protective' located in the food additives list, first used in 1988 as a natural preservative by prohibiting of antibiotics using in food in the US. Nowadays in more than 50 countries, there have been more successful implementation of the nisin protected up the food from milk and dairy products to canned foods many food products

  13. 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 avoid development of resistant strains. The combination of bacteriocins and physical treatments like high pressure processing or pulsed electric fields also offer good opportunities for more effective preservation of foods, providing an additional barrier to more refractile forms like bacterial endospores as well. The effectiveness of bacteriocins is often dictated by environmental factors like pH, temperature, food composition and structure, as well as the food microbiota. Foods must be considered as complex ecosystems in which microbial interactions may have a great influence on the microbial balance and proliferation of beneficial or harmful bacteria. Recent developments in molecular microbial ecology can help to better understand the global effects of bacteriocins in food ecosystems, and the study of bacterial genomes may reveal new sources of bacteriocins.

  14. Biopreservation in modified atmosphere packaged vegetables.

    NARCIS (Netherlands)

    Bennik, M.H.J.

    1997-01-01

    Recent trends in food preservation are the use of mild preservation techniques, such as modified atmosphere (MA) packaging and refrigeration, to prolong the shelflife of foods without affecting the fresh character of the product. This has resulted in the development of a new generation of chill stor

  15. Biopreservative in Foods: Nisin (E234)

    OpenAIRE

    Başar Uymaz; Pınar Şanlıbaba

    2015-01-01

    Fermentation is the oldest traditional method in order to protect against spoilage and pathogenic microorganisms. Thermal treatment, pH and water activity lowering and preservative addition other food preservation techniques that are commonly used. Although, as preservatives, many improved antibiotic and chemical agents have been gained, there are some other factors such as rapid resistance to antibiotics used in bacteria, in order to limit their use in food, to be found dimensions of threate...

  16. Feed grain improvement through biopreservation and bioprocessing

    OpenAIRE

    Olstorpe, Matilda

    2008-01-01

    Fermentation is an environmentally friendly method to improve feed quality. Fermented liquid feed and airtight stored moist crimped cereal grain systems that are of increasing importance in agricultural practice were studied. Both rely on spontaneous microbial developments with poorly understood population dynamics, resulting in unpredictable final quality. Temperature, fermentation time and ingredients affected final properties of the feed. Molecular-based species identification showed that ...

  17. 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.

  18. Optimization of lactic ferment with quinoa flour as bio-preservative alternative for packed bread.

    Science.gov (United States)

    Dallagnol, Andrea Micaela; Pescuma, Micaela; Rollán, Graciela; Torino, María Inés; de Valdez, Graciela Font

    2015-05-01

    The consumers' demand for food with high nutritional quality and free of chemical additives increases the need to look for new products and preservation strategies. Quinoa (Chenopodium quinoa) is an Andean pseudocereal highly appreciated because of its nutritional properties. Moreover, it is an optimal substrate for growing and production of improved amounts of antifungal compounds by Lactobacillus plantarum CRL 778. The aim of this work was to optimize a lactic ferment for packaged breads with improved nutritional value and prolonged shelf life by applying a statistical experimental design model. The addition of 30 % quinoa to the wheat semiliquid ferment (QWF) could highly improve the amino acids release (4.3 g/L) during fermentation. Moreover, this quinoa proportion was sufficient to obtain the same concentration of the antifungal compounds, phenyllactic and hydroxiphenyllactic acids (PLA and OH-PLA) as with 100 % quinoa (ca. 36 and 51 mg/L, respectively). Statistical model analysis showed that citrate and skimmed milk enhanced significantly all evaluated parameters specially PLA (ca. 71 mg/L), HO-PLA (ca. 75 mg/L), and lactate (27 g/L) with a p value <0.005. The synergic effects of higher antifungal compounds production, acid release, and pH decrease allowed lowering the amount (about 50 %) of the chemical preservative calcium propionate commonly added to bread. Moreover, these breads show increased shelf life.

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

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    Neha Sharma

    2013-10-01

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

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

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    Evandro Leite de Souza

    2005-07-01

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

  1. Partial characterisation of pediocin PO2 and comparison with nisin for biopreservation of meat products.

    Science.gov (United States)

    Coventry, M J; Muirhead, K; Hickey, M W

    1995-07-01

    A plasmid associated bacteriocin (pediocin PO2) was isolated by ammonium sulphate precipitation from cell-free growth media and subsequent studies showed that the partially purified pediocin PO2 was most likely identical (molecular mass approximately 3200 daltons in size by SDS-PAGE, stable to low pH and heat at 121 degrees C for 15 min, inactivated by various proteolytic enzymes and resistant to treatment with a range of solvents, except 10% formaldehyde) to other pediocins (PA-1 and AcH) previously reported. The antagonistic spectrum of activity of pediocin PO2 was compared with nisin and showed a narrower host-range, but a much greater activity against Listeria species including strains of Listeria monocytogences, than did nisin. A rapid method of reflectance colorimetry was used to quantitate growth and acid production (as determined by the colour change in bromcresol purple) of Lactobacillus curvatus, added to a meat product model system. The combined effects of refrigeration temperature, microbial load and bacteriocin concentration were determined in the model over 15 days storage. Both nisin and pediocin demonstrated inhibitory activity against Lactobacillus curvatus in the model system. However, when bacteriocins were incorporated into a manufactured cooked meat product only low nisin activity and no pediocin activity was detected, after challenge of vacuum packaged slices of product with Lactobacillus curvatus, over a 21 day storage trial under refrigeration temperatures.

  2. Physiology of Listeria monocytogenes in relation to food components and biopreservation.

    NARCIS (Netherlands)

    Verheul, A.

    1997-01-01

    Listeria monocytogenes is an important foodborne pathogen that has been responsible for severe infections in humans. The ubiquitous distribution of L. monocytogenes in the environment and its ability to grow at refrigeration temperature and at high osmolarity are of paramount importance for its haz

  3. The four-component aureocin A70 as a promising agent for food biopreservation.

    Science.gov (United States)

    Carlin Fagundes, Patrícia; Miceli de Farias, Felipe; Cabral da Silva Santos, Olinda; Souza da Paz, Juliana Aparecida; Ceotto-Vigoder, Hilana; Sales Alviano, Daniela; Villela Romanos, Maria Teresa; de Freire Bastos, Maria do Carmo

    2016-11-21

    Aureocin A70 is the only four-component bacteriocin described to date. As it inhibits the growth of a wide range of Gram-positive bacteria, including Listeria monocytogenes strains isolated from food, its potential for improving food safety was investigated in this study. Aureocin A70 (10,240AU/mL) proved to be bactericidal, but not extensively lytic, against listerial strains. The antibacterial activity of aureocin A70 (16AU/mL) was then tested in UHT-treated skimmed milk inoculated with the food-associated L. monocytogenes L12 strain (4-log CFU/mL) during storage at 4°C for one week. Aureocin A70 caused a time-dependent reduction in the listerial viable cell counts (5.51-log units) up to 7days of incubation. Aureocin A70 was neither toxic to the Vero and the L-929 cell lines nor exhibited a hemolytic activity against sheep red blood cells. Aureocin A70 proved to be completely stable for one month at 25°C, 16weeks at 4°C and 20weeks at -20°C. Aureocin A70 exhibited a time-dependent susceptibility to simulated gastric juice and bile salts mimicking gastrointestinal conditions. The entrapment of aureocin A70 in an alginate/gelatin matrix revealed that this bacteriocin can be released from this matrix. Moreover, it remained adsorbed to and active on a low-density polyethylene plastic surface suggesting that aureocin A70 may be employed in bioactive packaging to control the growth of undesirable bacteria. Taken together these results suggest that aureocin A70 is a promising alternative to be used in food applications.

  4. Biopreservation of Brined Shrimp (Pandalus borealis) by Bacteriocins from Lactic Acid Bacteria.

    Science.gov (United States)

    Einarsson, H; Lauzon, H L

    1995-02-01

    In brined shrimp (ca. 3% NaCl), the effects of three different lactic acid bacteria bacteriocins (crude [6.54 x 10(sup10) U of bacteriocin activity {BU}/g] and purified [8.13 x 10(sup23) BU/g] nisin Z, carnocin UI49 [2.32 x 10(sup4) BU/g], and crude bavaricin A [2.78 BU/g]) on bacterial growth and shelf life were compared with those of a benzoate-sorbate solution (0.1% each [wt/wt]) and a control with no preservatives. The shelf life of shrimp subjected to the control treatment was found to be 10 days. Carnocin UI49 did not extend the shelf life, while crude bavaricin A (a cell-free supernatant of Lactobacillus bavaricus MI 401) resulted in a shelf life of 16 days, as opposed to 31 days with nisin Z for both its crude and purified forms. The benzoate-sorbate solution preserved the brined shrimp for the whole storage period (59 days). In the control, carnocin UI49, and crude bavaricin A treatments, a gram-positive flora dominated towards the end of the storage period while in the nisin Z treatment a gram-negative flora was more pronounced.

  5. Biopreservation of refrigerated and vacuum-packed Dicentrarchus labrax by lactic acid bacteria.

    Science.gov (United States)

    El Bassi, Leila; Hassouna, Mnasser; Shinzato, Naoya; Matsui, Toru

    2009-08-01

    Two lactic acid bacteria (LAB) were selected from 100 LAB isolated from various sea products to examine their use in Dicentrarchus labrax preservation. The isolates, tentatively named strain nr 3 and 7, were identified as Lactobacillus plantarum and L. pentosus, respectively. They showed antagonistic activity against psychrotroph, pathogenic, and coliform bacteria. The antagonistic activity of strain 3 was suggested to be by bacteriocins since activity was abolished by protease treatment, while that of strain 7 was due to the effect of pH decrease caused by the produced organic acids. Their use prevented total volatile basic nitrogen contents (TVB-N) and trimethylamine (TMA) to some extent, suggesting that inoculation could extend the period of storage.

  6. 生物防腐剂——细菌素%Biopreservative--Bacteriocins

    Institute of Scientific and Technical Information of China (English)

    赖毅东; 宁正祥

    2002-01-01

    天然食品防腐剂取代化学合成防腐剂是一种必然趋势.细菌素是一类安全、高效、无毒的天然食品防腐剂.本文阐述了细菌素的分类、抑菌机理、合成和修饰,并简要介绍了细菌素作为食品添加剂,在食品防腐保鲜中的应用.尽管目前Nisin等细菌素由于受到抑菌效果、价格等方面因素的限制,其应用尚不能完全取代化学防腐剂,但是它作为一类理想的天然食品防腐剂,应用前景将十分广阔.

  7. Effect of Biopreservatives on Storage Life of Papaya (Carica papaya L.

    Directory of Open Access Journals (Sweden)

    Fatema H. Brishti

    2013-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this experiment the effect on post-harvest preservation of papaya (Carica papaya L. fruit coated with either Aloe gel (AG; 100% or papaya leaf extract with Aloe gel (PLEAG; 1:1 was studied. To evaluate the role of coating on ripening behavior and quality of papaya the uncoated and coated fruits were stored and ripened at room temperature (25 °C-29 °C and 82-84% relative humidity. Physico-chemical properties were analyzed at 4 day intervals during the storage period. The incidence of disease attack was also visually observed. The overall results showed the superiority of AG and PLEAG coating in lengthening the shelf-life of papaya fruit compared to controls which showed significant decay from 6th day onward and complete decay within 12 days of storage. The AG and PLEAG coated fruits maintained their shelf life for 12 days and decayed at 16th day. The coated fruits also maintained their color, flavor and firmness up to 12 days of storage. An increase in ascorbic acid content (120.2 mg/100 g was also found in coated fruits in contrast to the control (59 mg/100 g. Only 27% disease incidence was observed in AG and 13% in PLEAG coated fruits as compared to control (100% during the storage period. The results of this study show that both AG and PLEAG coatings have excellent potential to be used on fresh produce to maintain quality and extend shelf-life.

  8. Potential of the virion-associated peptidoglycan hydrolase HydH5 and its derivative fusion proteins in milk biopreservation.

    Directory of Open Access Journals (Sweden)

    Lorena Rodríguez-Rubio

    Full Text Available Bacteriophage lytic enzymes have recently attracted considerable interest as novel antimicrobials against Gram-positive bacteria. In this work, antimicrobial activity in milk of HydH5 [a virion-associated peptidoglycan hydrolase (VAPGH encoded by the Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88], and three different fusion proteins created between HydH5 and lysostaphin has been assessed. The lytic activity of the five proteins (HydH5, HydH5Lyso, HydH5SH3b, CHAPSH3b and lysostaphin was confirmed using commercial whole extended shelf-life milk (ESL in challenge assays with 10(4 CFU/mL of the strain S. aureus Sa9. HydH5, HydH5Lyso and HydH5SH3b (3.5 µM kept the staphylococcal viable counts below the control cultures for 6 h at 37°C. The effect is apparent just 15 minutes after the addition of the lytic enzyme. Of note, lysostaphin and CHAPSH3b showed the highest staphylolytic protection as they were able to eradicate the initial staphylococcal challenge immediately or 15 min after addition, respectively, at lower concentration (1 µM at 37°C. CHAPSH3b showed the same antistaphyloccal effect at room temperature (1.65 µM. No re-growth was observed for the remainder of the experiment (up to 6 h. CHAPSH3b activity (1.65 µM was also assayed in raw (whole and skim and pasteurized (whole and skim milk. Pasteurization of milk clearly enhanced CHAPSH3b staphylolytic activity in both whole and skim milk at both temperatures. This effect was most dramatic at room temperature as this protein was able to reduce S. aureus viable counts to undetectable levels immediately after addition with no re-growth detected for the duration of the experiment (360 min. Furthermore, CHAPSH3b protein is known to be heat tolerant and retained some lytic activity after pasteurization treatment and after storage at 4°C for 3 days. These results might facilitate the use of the peptidoglycan hydrolase HydH5 and its derivative fusions, particularly CHAPSH3b, as biocontrol agents for controlling undesirable bacteria in dairy products.

  9. Peroxidase activity and sensory quality of ready to cook mixed vegetables for soup: combined effect of biopreservatives and refrigerated storage

    Directory of Open Access Journals (Sweden)

    María Victoria Alvarez

    2015-03-01

    Full Text Available Enzymatic senescence processes and browning of fresh cut vegetables negatively affect their sensory properties and nutritional value and finally result in the rejection of affected products by consumers. In order to prevent quality decay, the combined effects of natural antioxidants and storage temperature on peroxidase activity and sensory attributes (overall visual quality, browning and odor of individual and mixed vegetables for soup (butternut squash, leek and celery were evaluated. Fresh cut vegetables were treated with antioxidant solutions as tea tree essential oil (15 μl/mL, propolis extract (15 μl/mL and gallic acid (2 mg/mL and stored at optimal (5 °C and abusive (15 °C temperature for a maximum of 14 days. The application of natural preservatives, plus optimal storage conditions, exerted significant inhibitory effects in peroxidase activity of squash, celery and mixed vegetables throughout the storage. Furthermore, propolis treatment applied on mixed vegetables retarded browning appearance and preserved the visual quality for a longer period when compared to untreated product.

  10. Inhibition of ochratoxigenic moulds by Debaryomyces hansenii strains for biopreservation of dry-cured meat products

    DEFF Research Database (Denmark)

    Andrade, Maria J.; Thorsen, Line; Rodríguez, Alicia

    2014-01-01

    overall in vitro inhibition of ochratoxigenic mould growth, and was therefore chosen for co-cultivation assays in dry-cured ham slices incubated at 0.94 and 0.84 a(w) simulating ham ripening. Regardless of the experimental conditions tested, lower levels of the inoculated P. nordicum strain were detected...... mould growth and OTA accumulation in dry-cured meat products. The inoculation of D. hansenii should be made at the beginning of processing (at the end of post salting) when the a(w) of the product is still high (near 0.94). This action in addition to application of appropriate hygienic actions...

  11. 生物防腐剂在酱油包装物灭菌上的应用%Application of bio-preservative in sterilization of sauce package

    Institute of Scientific and Technical Information of China (English)

    张丽华; 何余堂; 刘岩

    2007-01-01

    为了防止成品酱油的再发酵与生白镤,利用生物防腐剂(Nisin),对酱油包装袋进行灭菌,能够防止酱油由于包装而造成的二次污染的问题,延长了袋装酱油的货架期.

  12. A potential food biopreservative, CecXJ-37N, non-covalently intercalates into the nucleotides of bacterial genomic DNA beyond membrane attack.

    Science.gov (United States)

    Liu, Dongliang; Liu, Jun; Li, Jinyao; Xia, Lijie; Yang, Jianhua; Sun, Surong; Ma, Ji; Zhang, Fuchun

    2017-02-15

    The antibacterial activities and mechanism of an amide-modified peptide CecXJ-37N were investigated in this study. CecXJ-37N showed small MICs (0.25-7.8μM) against eight harmful strains common in food industry. The α-helix proportion of CecXJ-37N increased by 11-fold in prokaryotic membrane comparable environments; cytotoxicity studies demonstrated the MHC was significantly higher than that of non-amidated isoform. Moreover, CecXJ-37N possessed stronger capacities to resist trypsin and pepsin hydrolysis within two hours. Flow cytometry and scanning electron microscopy demonstrated that CecXJ-37N induced pore-formation, morphological changes, and lysed E. coli cells. Fluorescence microscopy indicated that CecXJ-37N penetrated E. coli membrane and accumulated in cytoplasm. Further ultraviolet-visible spectroscopy suggested that CecXJ-37N changed the action mode of parental peptide interacting with bacterial genome from outside binding to a tightly non-covalent intercalation into nucleotides. Overall, this study suggested that amide-modification enhanced antimicrobial activity and reduced the cytotoxicity, thus could be potential strategies for developing novel food preservatives.

  13. 乳酸菌抗真菌生物防腐剂作用机理和前景展望%Mechanisms of lactic acid bacteria as antifungal biopreservative and expectation of its prospects

    Institute of Scientific and Technical Information of China (English)

    成妮妮

    2012-01-01

    Foods are subject to be contaminated by moulds and their mycotoxin during storage,which has serious health hazard.Many researches found that some lactic acid bacteria(LAB) can inhibit mould growth and absorb mycotoxin through producing organic acid,short peptide,hydrogen peroxide and the absorption abilities of itself,reduce the content of mould and mycotoxin in food and extend the shelf-life.The researches of metabolic product and antifungal activity of LAB indicated that LAB had very good application prospect and hopeful became a safety food additive.%食品在储藏过程中易受霉菌及其产生的毒素的污染,严重危害人类健康。许多研究发现有些乳酸菌能够通过产生的有机酸、短肽、过氧化氢、以及其自身的吸附能力等抑制霉菌生长,吸附真菌毒素,以降低食品中霉菌及其毒素的含量,延长食品货架期。对乳酸菌的代谢产物及其抗真菌活性的深入研究表明,乳酸菌作为生物防腐剂具有良好的应用前景,有望成为安全的食品添加剂。

  14. Effects of biopreservative combined with partial freezing storage on fresh-keeping of Ruditapes variegata%生物保鲜剂结合微冻保藏对杂色蛤肉的保鲜作用

    Institute of Scientific and Technical Information of China (English)

    齐凤生; 李丽娜; 刘红英

    2014-01-01

    Objective To evaluate fresh-keeping effect of the biological preservatives under partial freezing condition. Methods Disposed with lysozyme, nisin and vacuum packaging, the meat of Ruditapes variegata was examined for its total bacterial count(TBC) and evaluated for its physical and chemical index during its storage under the temperature of (-3±0.5)℃, and fresh-keeping effect of the biological preservatives under partial freezing condition was also evaluated. Results The results showed that after storage under the temperature of -3 ℃ for 25 d, total volatile basic nitrogen (TVB-N) of Ruditapes variegata meat was 14.73 mg/100 g and 14.92 mg/100 g respectively for disposing with lysozyme and nisin, which were within the nor-mal health standard of the national regulation. For the match-up of the two biological preservatives, TVB-N of Ruditapes variegata meat was 14.38 mg/100g after 30 d storage under -3 ℃, which could keep fresh 15 d longer than control sample. Changes of pH value, TBC, TVB-N, Thibabituric Acid (TBA) and Ca2+-ATPase ac-tivity of each disposed samples were all correlated with storage time (P<0.05). Comparing with other test groups, combined disposing of lysozyme and nisin achieved better fresh-keeping effect. Conclusion Dispos-ing of biological preservatives combined with partial freezing storage proves to effectively prolong the shelf life of Ruditapes variegata meat.%目的:评价生物保鲜剂在微冻条件下的保鲜作用。方法以杂色蛤肉为研究对象,经溶菌酶、乳酸链球菌素及真空包装处理,测定其在(-3±0.5)℃贮藏过程中的细菌总数、理化等指标的变化。结果在-3℃条件下贮藏25 d后,经溶菌酶、乳酸链球菌素处理的杂色蛤肉挥发性盐基氮分别达到了14.73 mg/100 g和14.92 mg/100 g,均接近国家规定的卫生标准;溶菌酶、乳酸链球菌素复合处理的杂色蛤肉贮藏30 d其挥发性盐基氮为14.38 mg/100 g,比未经处理的对照组延长了15 d以上。各处理组的pH值、细菌总数、挥发性盐基氮、硫代巴比妥酸和 Ca2+-ATPase 活性变化也均与贮藏时间相关(P<0.05)。结论相对于其他实验组,溶菌酶、乳酸链球菌素复合处理组保鲜效果最好。

  15. 天然生物保鲜剂Nisin应用蔬菜保鲜研究——以生菜为例%Application of Bio-preservative Nisin in Vegetable Preservation ---Taking Lettuce as an Example

    Institute of Scientific and Technical Information of China (English)

    吴涛; 辛松林; 王绍胜; 杜俊贵

    2011-01-01

    Nisin即乳酸链球菌素,是一种天然生物保鲜剂,试验用不同浓度保鲜剂溶液(20、40、60、80、100)mg/g对生菜进行处理并与用蒸馏水的处理进行比较,通过评价感官品质、失水率、呼吸强度、叶绿素含量和色度,结果发现40mg/g的Nisin溶液的处理有利于生菜贮藏期的延长。%Nisin,a polycyclic antibacterial peptide, can be used as a food preservative. The paper conducts a comparative study between distilled water and Nisin solutions of different concentrations ( 20,40,60,80,100 rag/g) on their preservation effects on lettuce in terms of sensory evaluation, dehydration rate, breath intensity, chlorophyll content and the chromaticity. The findings show that lettuce is best preserved with the 40mg/g Nisin solution.

  16. Research and application of lactic acid bacteria as seafood bio-preservation agent%乳酸菌作为海产品生物保鲜剂的研究与应用

    Institute of Scientific and Technical Information of China (English)

    吕欣然; 白凤翎; 励建荣

    2014-01-01

    乳酸菌作为传统发酵食品的微生物类群栖息在各种自然环境中,在海洋动物及加工海产品中也存在相当数量的各种乳酸菌.由于乳酸菌具有良好的生物拮抗活性,作为生物保鲜剂已被广泛应用于生鲜及加工食品领域.该文对海产品中的乳酸菌资源,乳酸菌作为海产品生物防腐剂的条件和优势,以及控制海产品中微生物的作用效果进行了综述,为进一步挖掘乳酸菌资源、研发针对性生物保鲜制剂在海产品保鲜中的应用提供参考.

  17. THE IMPORTANCE OF BACTERIOCINS IN MEAT AND MEAT PRODUCTS

    Directory of Open Access Journals (Sweden)

    Meltem SERDAROĞLU

    2000-03-01

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

  18. 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

    microbiota was in all treatments dominated by lactic acid bacteria and coliforms and no changes in the rat commensal microbiota were detected after ingestion of either of the two L plantarum strains as determined by both culturable methods and molecular methods (DGGE). Both strains were detected......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...

  19. [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.

  20. 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

  1. 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.

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

    Science.gov (United States)

    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.

  3. Spontaneous nisin-resistant Listeria monocytogenes mutants with increased expression of a putative penicillin-binding protein and their sensitivity to various antibiotics

    DEFF Research Database (Denmark)

    Gravesen, Anne; Sorensen, K.; Aarestrup, Frank Møller

    2001-01-01

    A concern regarding the use of bacteriocins, as for example the lantibiotic nisin, for biopreservation of certain food products is the possibility of resistance development and potential cross-resistance to antibiotics in the target organism. The genetic basis for nisin resistance development...

  4. Complete Chromosome Sequence of Carnobacterium maltaromaticum LMA 28

    DEFF Research Database (Denmark)

    Cailliez-Grimal, Catherine; Chaillou, Stéphane; Anba-Mondoloni, Jamila;

    2013-01-01

    Within the lactic acid bacterium genus Carnobacterium, Carnobacterium maltaromaticum is one of the most frequently isolated species from natural environments and food. It potentially plays a major role in food product biopreservation. We report here on the 3.649-Mb chromosome sequence of C. malta....... maltaromaticum LMA 28, which was isolated from ripened soft cheese....

  5. Growth control of Listeria monocytogenes on cold-smoked salmon using a competitive lactic acid bacteria flora

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Gram, Lone; Huss, Hans Henrik

    1999-01-01

    A Lactobacillus sake strain LKE5 and four strains of Carnobacterium piscicola were evaluated as biopreservation cultures to control the growth of Listeria monocytogenes on vacuum-packed. cold-smoked salmon stored at 5 degrees C. All five strains were antilisterial as live cultures in an agar...

  6. Microemulsions as Potential Carriers of Nisin

    DEFF Research Database (Denmark)

    Chatzidaki, Maria D; Papadimitriou, Konstantinos; Alexandraki, Voula

    2016-01-01

    Water-in-oil (W/O) microemulsions based on either refined olive oil (ROO) or sunflower oil (SO), distilled monoglycerides (DMG), and ethanol were used as nisin carriers in order to ensure its effectiveness as a biopreservative. This work presents experimental evidence on the effects of ethanol...

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

  10. 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.

  11. Improved applicability of nisin in novel combinations with other food preservation factors

    OpenAIRE

    Pol, I.E.

    2001-01-01

    General discussionModern consumers nowadays, have a preference for more natural, mildly preserved food products with a fresh appearance over traditionally preserved products. Mild preservation techniques applied singly are usually not sufficient to control microbial outgrowth and combinations of measures are needed to ensure complete safe products (16). Bacteriocins, produced by lactic acid bacteria have been successfully used as biopreservatives in a number of food products to inhibit the gr...

  12. PRODUCCIÓN Y RECUPERACIÓN DE SUSTANCIAS BIOCONSERVANTES A PARTIR DE CULTIVOS INICIADORES DE PRODUCTOS CÁRNICOS-CURADOS

    OpenAIRE

    DE JESUS DE BARROS, CARLOS ALBERTO

    2017-01-01

    The aim of this thesis was to study the technological possibilities of producing biopreservatives for meat products using the by-products obtained from the fermentation process of two strains of lactic acid bacteria, Lactobacillus plantarum and Pediococcus pentosaceus. Both are part of the collection of starter cultures of the collaborating company of this project, and are marketed for this purpose. In the first part of this project, the conditions of industrial production of starter cultu...

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

    OpenAIRE

    Luis A. Aguado Bautista; Yenizey M. Álvarez Cisneros; Edith Ponce Alquicira

    2010-01-01

    Biopreservation can be defined as the foods shelf life extension employing antibacterial products like bacteriocins. The objective of this work was to determinate the efficacy of E. faecium MXVK29 bacteriocin in combination with chemical preservatives against spoilage and pathogens microorganisms. Bacteriocin raw extrac antimicrobial activity was 46.34 UA/g of protein. Growth of Pseudomonas putida was not affected by the preservatives employed at the conditions employed. Antimicrobial respon...

  14. THE IMPORTANCE OF BACTERIOCINS IN MEAT AND MEAT PRODUCTS

    OpenAIRE

    Serdaroğlu, Meltem; Meltem SAPANCI ÖZSÜMER

    2000-01-01

    There is an increasing consumer demand for food products which are free of chemical additives, reduced in salt and processed as little as possible. These minimally processed foods require special application to assure their microbiological safety. The use of microorganisms and enzymes for food preservatives is called biopreservation. The most important group of microorganisms with antimicrobial effect used in the production of foods is the lactic acid bacteria. In meats although lactic acid b...

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

    OpenAIRE

    Dortu C.; Thonart P.

    2009-01-01

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

  16. Growth control of Listeria innocua 2030c on vacuum-packaged cold-smoked salmon by lactic acid bacteria.

    Science.gov (United States)

    Tomé, Elisabetta; Gibbs, Paul A; Teixeira, Paula C

    2008-02-10

    Five bacteriocin-producing lactic acid bacteria (LAB): Enterococcus faecium ET05, Lactobacillus curvatus ET06, L. curvatus ET30, L. deldrueckii ET32 and Pediococcus acidilactici ET34, selected by their capacity for growth and producing inhibition in vitro at high salt-on-water content, low temperature and anaerobic atmosphere, conditions simulating cold-smoked fish, were inoculated onto salmon fillets, in co-culture with Listeria innocua 2030c, and cold-smoked processed (dry salted for 6 h; drying for 6 h; smoke for 2 h). The finished product was then packed under vacuum and stored at 5 degrees C. Enumeration of LAB and L. innocua was performed during storage. Results showed that strain E. faecium ET05 was the best biopreservative candidate for controlling L. innocua growth in vacuum-packaged cold-smoked salmon (CSS) processed under the salting/drying/smoking parameters referred above. L. curvatus ET30 and L. delbrueckii ET32 also showed a good biopreservation potential for CSS although they were less effective than the former. L. curvatus ET06 and P. acidilactici ET34 showed a bacteriostatic mode of action against the target bacteria in vitro as well as when inoculated into the salmon fillets. This study describes a potential application of five different LAB in the biopreservation of Listeria in CSS.

  17. Effect of reuterin-producing Lactobacillus reuteri coupled with glycerol on the volatile fraction, odour and aroma of semi-hard ewe milk cheese.

    Science.gov (United States)

    Gómez-Torres, Natalia; Ávila, Marta; Delgado, David; Garde, Sonia

    2016-09-02

    The effect of the biopreservation system formed by Lactobacillus reuteri INIA P572, a reuterin-producing strain, and glycerol (required for reuterin production), on the volatile fraction, aroma and odour of industrial sized semi-hard ewe milk cheese (Castellano type) was investigated over a 3-month ripening period. The volatile compounds were extracted and analyzed by SPME-GC-MS and cheese odour and aroma profiles were studied by descriptive sensory analysis. Control cheese was made only with a mesophilic starter and experimental cheeses with L. reuteri were made with and without glycerol. The addition of L. reuteri INIA P572 to milk enhanced the formation of six volatile compounds. Despite the changes in the volatile compounds profile, the use of L. reuteri INIA P572 did not noticeably affect the sensory characteristics of cheese. On the other hand, the addition of L. reuteri INIA P572 coupled with 30mM glycerol enhanced the formation of twelve volatile compounds, but decreased the formation of five ones. The use of the biopreservation system did not affect overall odour and aroma quality of cheese although it resulted in a significant decrease of the odour intensity scores. In addition, this cheese received significant higher scores for "cheesy" aroma and significant lower scores for the aroma attributes "milky", "caramel" and "yogurt-like". The first two axes of a principal component analysis (PCA) performed for selected volatile compounds and sensory characteristics, accounting for 75% of the variability between cheeses, separated cheeses made with L. reuteri INIA P572 and glycerol from the rest of cheeses, and also differentiated control cheese from cheeses made with L. reuteri INIA P572 from day 60 onward. Our results showed that the reuterin-producing L. reuteri INIA P572 strain, when coupled with glycerol, may be a suitable biopreservation system to use in cheese without affecting odour and aroma quality.

  18. Antibacterial activity of Citrus reticulata peel extracts.

    Science.gov (United States)

    Jayaprakasha, G K; Negi, P S; Sikder, S; Rao, L J; Sakariah, K K

    2000-01-01

    Citrus peels were successively extracted with hexane, chloroform and acetone using a soxhlet extractor. The hexane and chloroform extracts were fractionated into alcohol-soluble and alcohol-insoluble fractions. These fractions were tested against different gram positive and gram negative bacteria. The EtOH-soluble fraction was found to be most effective. Fractionation of EtOH-soluble fraction on silica gel column yielded three polymethoxylated flavones, namely desmethylnobiletin, nobiletin and tangeretin. Their structures were confirmed by UV, 1H, 13C NMR and mass spectral studies. The findings indicated a potential of these natural compounds as biopreservatives in food applications.

  19. Metabolic footprinting for investigation of antifungal properties of Lactobacillus paracasei

    DEFF Research Database (Denmark)

    Honoré, Anders Hans; Aunsbjerg, Stina Dissing; Ebrahimi, Parvaneh

    2016-01-01

    Lactic acid bacteria with antifungal properties are applied for biopreservation of food. In order to further our understanding of their antifungal mechanism, there is an ongoing search for bioactive molecules. With a focus on the metabolites formed, bioassay-guided fractionation and comprehensive....... The antifungal properties were assessed by measuring mold growth of two Penicillium strains on cell-free ferments of three strains of Lactobacillus paracasei pre-fermented in a chemically defined medium. Exometabolomic profiling was performed by reversed-phase liquid chromatography in combination with mass...

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

    Directory of Open Access Journals (Sweden)

    Dortu C.

    2009-01-01

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

  1. 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.

  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. 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

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

    Directory of Open Access Journals (Sweden)

    Luis A. Aguado Bautista

    2010-12-01

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

  5. 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.

  6. 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.

  7. Biomedical applications of nisin.

    Science.gov (United States)

    Shin, J M; Gwak, J W; Kamarajan, P; Fenno, J C; Rickard, A H; Kapila, Y L

    2016-06-01

    Nisin is a bacteriocin produced by a group of Gram-positive bacteria that belongs to Lactococcus and Streptococcus species. Nisin is classified as a Type A (I) lantibiotic that is synthesized from mRNA and the translated peptide contains several unusual amino acids due to post-translational modifications. Over the past few decades, nisin has been used widely as a food biopreservative. Since then, many natural and genetically modified variants of nisin have been identified and studied for their unique antimicrobial properties. Nisin is FDA approved and generally regarded as a safe peptide with recognized potential for clinical use. Over the past two decades the application of nisin has been extended to biomedical fields. Studies have reported that nisin can prevent the growth of drug-resistant bacterial strains, such as methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Enterococci and Clostridium difficile. Nisin has now been shown to have antimicrobial activity against both Gram-positive and Gram-negative disease-associated pathogens. Nisin has been reported to have anti-biofilm properties and can work synergistically in combination with conventional therapeutic drugs. In addition, like host-defence peptides, nisin may activate the adaptive immune response and have an immunomodulatory role. Increasing evidence indicates that nisin can influence the growth of tumours and exhibit selective cytotoxicity towards cancer cells. Collectively, the application of nisin has advanced beyond its role as a food biopreservative. Thus, this review will describe and compare studies on nisin and provide insight into its future biomedical applications.

  8. A ready-to-use antifungal starter culture improves the shelf life of packaged bread.

    Science.gov (United States)

    Gerez, C L; Torino, M I; Obregozo, M D; Font de Valdez, G

    2010-04-01

    Fungal spoilage is the main cause of economic loss in the baking industry. In this study, we developed a ready-to-use biopreserver (slurry [SL]) for nonsliced packed bread by using selected antifungal lactic acid bacteria (LAB) and low-cost ingredients that are compatible with the food matrix. Four LAB strains (Lactobacillus brevis CRL 772, L. brevis CRL 796, L. plantarum CRL 778, and L. reuteri CRL 1100) tested in bread preservation were able to inhibit Penicillium sp. growth and lengthen shelf life twofold with respect to breads prepared using only Saccharomyces cerevisiae (2 days shelf life). The best biopreservation effect (5 days shelf life) was obtained with 40% antifungal slurry SL778 containing L. plantarum CRL 778; this was as effective as 0.2% calcium propionate (PCa). The antifungal effect of SL778 was related to the synthesis of acetic and phenyllactic acid as well as lactic acid, which was produced at a high concentration (31.2 mmol/kg) and lowered the pH of the dough, favoring the undissociated fraction of the organic acids. The combination of the starter SL778 with 0.4% PCa extended the shelf life of packaged bread to 24 days, 2.6-fold longer than breads prepared with only 0.4% PCa.

  9. Food preservative potential of gassericin A-containing concentrate prepared from a cheese whey culture supernatant from Lactobacillus gasseri LA39.

    Science.gov (United States)

    Nakamura, Kiyoshi; Arakawa, Kensuke; Kawai, Yasushi; Yasuta, Narimi; Chujo, Takahiro; Watanabe, Masamichi; Iioka, Hiroyuki; Tanioka, Masashi; Nishimura, Junko; Kitazawa, Haruki; Tsurumi, Koichi; Saito, Tadao

    2013-02-01

    Gassericin A (GA) is a circular bacteriocin produced by Lactobacillus gasseri LA39. In this study, GA-containing concentrate was prepared using a cross-flow membrane filtration device (30 kDa cut-off) from the culture supernatant of Lb. gasseri LA39 cultivated in a cheese whey-based food-grade medium. The bacteriocin activity titer in the concentrate was 16 times as high as that of the culture supernatant and was completely maintained through each incubation at 4°C for 3 months, 37°C for 2 months, 60°C for 5 h, and 100°C for 30 min. The GA-containing concentrate was used with glycine powder to make custard creams, and then four representative strains of custard cream spoilage bacteria (Bacillus cereus, Lactococcus lactis subsp. lactis, Achromobacter denitrificans and Pseudomonas fluorescens) were individually inoculated at c. 10(3) colony forming units/g in the custard creams. Throughout 30 days of incubation at 30°C, all of the inoculated bacteria were completely inhibited by the combination of 5% (w/w) of the GA-containing concentrate and 0.5% (w/w) glycine. This is the first highly practical application of GA to foods as a biopreservative, and the concentration method and the bacteriocin concentrate would contribute to biopreservation of several foods.

  10. 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...

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

    Science.gov (United States)

    Garcha, Seema; Natt, Navdeep Kaur

    2012-10-01

    A challenge for food industry today is to produce minimally processed food, without use of chemical preservatives and little compromise on nutritional status. Lactobacillus acidophilus NCDC 291 can be directly added to food where it enhances shelf life by competing with other microflora (both bacterial and fungal) for food and also by production of antimicrobial metabolites as bacteriocins. Comprehensive studies have demonstrated the in vitro activity of bacteriocins. However their role in preventing fresh food spoilage needs more elucidation. The present study was conducted to evaluate the efficacy of the whole cells of this organism as biopreservative agent against fungi. Four most commonly occurring spoilage fungi were isolated and were identified as Fusarium, Alternaria, Penicillium and Aspergillus. Growth of all of them was inhibited in in vitro studies, (approximately 33-43% decrease in mycelial dry weight basis between test and control). In situ biopreservation of Indian cheese and raw poultry meat was attempted and the colony count of Alternaria was significantly (p < 0.05, Bonferroni Holm) reduced in presence of L. acidophilus. Dip and Keep approach of preservation for Mangifera and Momordica were carried out in which microbial spoilage was not observed up to 6 days.

  12. 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.

  13. Improving simultaneously the quality and safety of cooked and peeled shrimp using a cocktail of bioprotective lactic acid bacteria.

    Science.gov (United States)

    Saraoui, Taous; Cornet, Josiane; Guillouet, Emilie; Pilet, Marie France; Chevalier, Frédérique; Joffraud, Jean-Jacques; Leroi, Françoise

    2017-01-16

    Tropical shrimp is of considerable economic importance in the world but is highly perishable due to microbial and chemical degradation. Biopreservation is a food preservation technology based on the addition of "positive" bacteria able to kill or prevent the growth of undesirable microorganisms. Two strains of lactic acid bacteria (LAB) have previously been selected for a biopreservation strategy: Lactococcus piscium CNCM I-4031, for its ability to prevent the sensory deterioration of seafood and Carnobacterium divergens V41, which inhibits growth of Listeria monocytogenes. The objective was to test the association of the two strains to improve both the quality and safety of shrimp. In a first trial, the two LAB were inoculated alone or in a cocktail in cooked and peeled shrimp (CPS) Penaeus vannamei at 5×10(5)CFU/g. Chemical, sensory and microbiological analyses by culture-dependent and -independent methods were performed during storage under modified atmosphere packaging (MAP) at 8°C. The results were compared to a non-inoculated batch. In a second trial, the same experiments were repeated in the presence of 10(2)CFU/g of L. monocytogenes RF191. The microbiota of CPS was composed of LAB, Shewanella spp. and Enterobacteriaceae. Brochothrix thermosphacta was not detected. L. piscium and C. divergens reached 10(8) and 10(9)CFU/g, respectively, in 7days and did not inhibit each other when co-inoculated. L. piscium reduced L. monocytogenes by 1Log (CFU/g) for 28days. C. divergens had an immediate listericidal effect lasting 7days. A regrowth of L. monocytogenes was then observed but the count was always 2 to 5Log (CFU/g) lower than in the control. No additional or synergic effect between protective strains was observed and the cocktail had the same inhibitory effect as C. divergens alone. C. divergens was very effective at preventing the sensory deterioration of CPS. This may be related to the inhibition of Shewanella and Enterobacteriaceae. However, the panelists

  14. The Use of Plant Antimicrobial Compounds for Food Preservation.

    Science.gov (United States)

    Hintz, Tana; Matthews, Karl K; Di, Rong

    2015-01-01

    Foodborne disease is a global issue with significant impact on human health. With the growing consumer demand for natural preservatives to replace chemical compounds, plant antimicrobial compounds must be thoroughly investigated for their potential to serve as biopreservatives. This review paper will focus on the plant-derived products as antimicrobial agents for use in food preservation and to control foodborne pathogens in foods. Structure, modes of action, stability, and resistance to these plant compounds will be discussed as well as their application in food industries and possible technologies by which they can be delivered. Benefits as well as challenges, such as the need for further research for implementation and governmental regulation, will be highlighted.

  15. Bacteriophage biocontrol of foodborne pathogens.

    Science.gov (United States)

    Kazi, Mustafa; Annapure, Uday S

    2016-03-01

    Bacteriophages are viruses that only infect bacterial cells. Phages are categorized based on the type of their life cycle, the lytic cycle cause lysis of the bacterium with the release of multiple phage particles where as in lysogenic phase the phage DNA is incorporated into the bacterial genome. Lysogeny does not result in lysis of the host. Lytic phages have several potential applications in the food industry as biocontrol agents, biopreservatives and as tools for detecting pathogens. They have also been proposed as alternatives to antibiotics in animal health. Two unique features of phage relevant for food safety are that they are harmless to mammalian cells and high host specificity, keeping the natural microbiota undisturbed. However, the recent approval of bacteriophages as food additives has opened the discussion about 'edible viruses'. This article reviews in detail the application of phages for the control of foodborne pathogens in a process known as "biocontrol".

  16. Effects of Lactic Acid Bacteria Fermentation on the Quality of Little Yellow Croaker

    Directory of Open Access Journals (Sweden)

    Yuan Wu

    2013-11-01

    Full Text Available This research was to study the effects of lactic acid bacteria fermentation on the quality of little yellow croaker. The effects of the LAB starter composed of Lactobacillus plantarum and Lactobacillus acidophilus on the quality of little yellow croaker were studied through a 72 h fermentation process in this study. During 72 h fermentation at 30°C, little yellow croaker inoculated with the LAB starter not only resulted in a rapid pH decrease and suppression of spoilage bacteria, but also receded chemical changes such as total volatile base nitrogen and biogenic amines, its texture profile and whiteness also satisfying. Besides, Scanning Electron Micrograph (SEM images indicated some microstructure changes in LAB fermentation. The results demonstrated that the LAB starter could be developed as bio-preservatives to improve the quality of little yellow croaker in storage.

  17. Role of lactic acid bacteria during meat conditioning and fermentation: peptides generated as sensorial and hygienic biomarkers.

    Science.gov (United States)

    Fadda, Silvina; López, Constanza; Vignolo, Graciela

    2010-09-01

    The microbial ecology of meat fermentation is a complex process in which lactic acid bacteria (LAB) and coagulase-negative cocci play a major role. The present work reviews the most significant developments in which LAB are the main characters acting both as starter cultures improving the sensorial quality and as biopreservative agents. New findings about the identification of low molecular weight peptides arisen from protein hydrolysis in dry fermented sausages and their relation with flavor is presented. Also, a brief description of a proteomic approach is detailed in order to exemplify its application as a tool in the search for improved LAB strains that will contribute to food quality and safety. Finally, the most important features of bacteriocinogenic LAB and its bacteriocins in bioprotection of meat and meat products are analyzed.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Spray drying for preservation of erythrocytes: effect of atomization on hemolysis.

    Science.gov (United States)

    McLean, Mary; Han, Xiao-Yue; Higgins, Adam Z

    2013-04-01

    Spray drying has the potential to enable storage of erythrocytes at room temperature in the dry state. The spray drying process involves atomization of a liquid into small droplets and drying of the droplets in a gas stream. In this short report, we focus on the atomization process. To decouple atomization from drying, erythrocyte suspensions were sprayed with a two-fluid atomizer nozzle using humid nitrogen as the atomizing gas. The median droplet size was less than 100 μm for all of the spray conditions investigated, indicating that the suspensions were successfully atomized. Hemolysis was significantly affected by the hematocrit of the erythrocyte suspension, the suspension flow rate, and the atomizing gas flow rate (pspray drying may be a feasible option for erythrocyte biopreservation.

  20. Research on Characteristics of Nisin and the Application in Food Industry%乳酸链球菌肽的特性及其在食品工业中的应用

    Institute of Scientific and Technical Information of China (English)

    孙兆竹; 申秋华; 白文杰

    2013-01-01

    乳酸链球菌素是由乳酸链球菌产生的一种高效、无毒、安全、无副作用的天然食品防腐剂.介绍了乳酸链球菌素(Nisin)的特性及其抑菌防腐机理,并就其在食品工业中的应用加以论述.%Nisin is a kind of high efficiency and non-poisonous effect natural bio-preservative food antiseptic produced by Lactococcus lactis.The characteristics and antibiotic mechanism of Nisin were introduced,as well as the application in food industry.

  1. Metabolic Profiling of Food Protective Cultures by in vitro NMR Spectroscopy

    DEFF Research Database (Denmark)

    Ebrahimi, Parvaneh

    D project is mainly focused on the application of in vitro NMR spectroscopy for studying the metabolism of protective cultures. As an important part of this work, an analytical protocol was developed for realtime in vitro NMR measurements of bacterial fermentation, which includes guidelines from the sample......Food spoilage is of major concern to the food industry, because it leads to considerable economic losses, a deteriorated environmental food-print, and to possible public health hazards. In order to limit food spoilage, research on the preservation of food products has always received particular......-called protective cultures) has unexploited potential to inhibit the growth of pathogenic microorganisms and enhance the shelf life of the final food product. In order to apply biopreservation in food products effectively, detailed knowledge on the metabolism of protective cultures is required. The present Ph...

  2. Production of medium chain saturated fatty acids with enhanced antimicrobial activity from crude coconut fat by solid state cultivation of Yarrowia lipolytica.

    Science.gov (United States)

    Parfene, Georgiana; Horincar, Vicentiu; Tyagi, Amit Kumar; Malik, Anushree; Bahrim, Gabriela

    2013-02-15

    Fatty acids profiles and antimicrobial activity of crude coconut fat hydrolysates obtained in solid-state cultivation system with a selected yeast strain Yarrowia lipolytica RO13 were performed. A preliminary step regarding extracellular lipase production and solid state enzymatic hydrolysis of crude fat at different water activity and time intervals up to 7 days was also applied. Gas chromatography-mass spectrometry analysis was used for quantification of medium chain saturated fatty acids (MCSFAs) and the results revealed a higher concentration of about 70% lauric acid from total fatty acids. Further, antimicrobial activity of fatty acids against some food-borne pathogens (Salmonella enteritidis, Escherichia coli, Listeria monocytogenes and Bacillus cereus) was evaluated. The minimum inhibitory concentration of the obtained hydrolysates varied from 12.5 to 1.56 ppm, significantly lower than values reported in literature. The results provide substantial evidence for obtaining biopreservative effects by coconut fat enzymatic hydrolysis.

  3. Bioprocess development for the production of sonorensin by Bacillus sonorensis MT93 and its application as a food preservative.

    Science.gov (United States)

    Chopra, Lipsy; Singh, Gurdeep; Jena, Kautilya Kumar; Verma, Himanshu; Sahoo, Debendra K

    2015-01-01

    Media composition and environmental conditions were optimized using statistical tools, Plackett Burman design and response surface methodology, to maximize the yield of a bacteriocin, named as sonorensin, from a new marine isolate Bacillus sonorensis MT93 showing broad spectrum of antimicrobial activity. Under optimized conditions, MT93 produced 15-fold higher yield of sonorensin compared to that under initial fermentation conditions. As oxygen supply is a critical parameter controlling growth and product formation in aerobic bioprocesses and used as a parameter for bioprocess scale up, the effects of oxygen transfer, in terms of volumetric oxygen transfer coefficient (kLa), on production of sonorensin was investigated using optimized medium composition in a bioreactor. Studies on effectiveness of sonorensin against Staphylococcus aureus and Listeria monocytogenes in fruit juice and as a preservative in pasteurized milk demonstrated its potential as a biopreservative in fruit products and shelf life extender of the pasteurized milk.

  4. 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.

  5. 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.

  6. A new hybrid bacteriocin, Ent35–MccV, displays antimicrobial activity against pathogenic Gram-positive and Gram-negative bacteria

    Science.gov (United States)

    Acuña, Leonardo; Picariello, Gianluca; Sesma, Fernando; Morero, Roberto D.; Bellomio, Augusto

    2012-01-01

    Bacteriocins and microcins are ribosomally synthesized antimicrobial peptides that are usually active against phylogenetically related bacteria. Thus, bacteriocins are active against Gram-positive while microcins are active against Gram-negative bacteria. The narrow spectrum of action generally displayed by bacteriocins from lactic acid bacteria represents an important limitation for the application of these peptides as clinical drugs or as food biopreservatives. The present study describes the design and expression of a novel recombinant hybrid peptide combining enterocin CRL35 and microcin V named Ent35–MccV. The chimerical bacteriocin displayed antimicrobial activity against enterohemorrhagic Escherichia coli and Listeria monocytogenes clinical isolates, among other pathogenic bacteria. Therefore, Ent35–MccV may find important applications in food or pharmaceutical industries. PMID:23650575

  7. 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.

  8. Use of Probiotic Microorganisms for Bio-Protective Aims

    Directory of Open Access Journals (Sweden)

    Filiz YANGILAR

    2015-03-01

    Full Text Available It was known that some diseases can be treated as the result of the use of antibiotics in certain periods and at certain dosages while inactivating and deteriorating normal microorganisms performing useful activities in human metabolism (in especially intestinal flora. It was occured that after the use of antibiotics, some defects can be seen resulting from antibiotics (such as allergy, diarrhea, gas formation etc. With this aim, nutraceutics and functional food have gained importance over the last years and consumers began to be interested in probiotics, natural antioxidants, dietary fibres, products with low calorie and cholesterol contents, especially the products containing probioticbacteria. Bacteriocins produced by probiotic bacteria can play important roles as food protective and safeguarding since they can compete with unwanted or pathogen microorganisms survive in the media and colonize in intestines. In this review, is aimed to emphasis bioprotective compounds, advantages and disadvantages of biopreservation method and the importance of the mechanisms of probiotic microorganisms.

  9. Research Progress of Fermentation and Purification Technique of Nisin%乳链菌肽的发酵及分离纯化工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    马赛箭; 安超

    2011-01-01

    Nisin is a bacteriocin produced by Lactococcus lactis and widely used as a safe and natural biopreservative in the food industry. This paper overviewed the present development of fermentation and purification of Nisin in the word, and the problems and solutions in the production process were analyzed.%乳链菌肽(Nisin)是由乳酸乳球菌代谢产生的细菌素,是一种天然、安全的生物防腐剂,被广泛应用于食品工业中.本文论述了近年来国内外乳链菌肽发酵及分离纯化工艺的技术概况,并对生产过程中存在的问题进行了分析.

  10. 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.

  11. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  12. Non-Conventional Tools to Preserve and Prolong the Quality of Minimally-Processed Fruits and Vegetables

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    Maria Rosaria Corbo

    2015-11-01

    Full Text Available The main topic of this paper is a focus on some non-conventional tools to preserve the microbiological and physico-chemical quality of fresh-cut fruits and vegetables. The quality of fresh-cut foods is the result of a complex equilibrium involving surface microbiota, storage temperature, gas in the headspace and the use of antimicrobials. This paper proposes a short overview of some non-conventional approaches able to preserve the quality of this kind of product, with a special focus on some new ways, as follows: (1 use of edible or antimicrobial-containing coatings (e.g., chitosan-based coatings on fruits or vegetables; (2 alternative modified atmospheres (e.g., high O2-modified atmosphere packaging (MAP or the use of essential oils in the headspace; (3 conditioning solutions with antimicrobials or natural compounds for fruit salad; and (4 biopreservation and use of a probiotic coating.

  13. How Biobanks Are Assessing and Measuring Their Financial Sustainability.

    Science.gov (United States)

    Brown, Tony; Kelly, Devon D; Vercauteren, Suzanne M; Wilson, William H; Werner, Alexander

    2017-02-01

    As guest editors of this sustainability issue of Biopreservation and Biobanking focused on business planning, utilization, and marketing, we invited a number of experts from different sectors of the biobanking arena to provide their views on business planning issues. Each expert was asked to provide a brief background statement on their biobanks, to build a context to understand their answers to the sustainability questions. We hope that these insights and experiences can provide valuable considerations and ideas for other biobanks who wish to develop or refine their own business plans, measure their utilization rates, and work toward financial sustainability. In addition, after the expert input was gathered, the guest editors invited an additional expert to provide summary comments and observations on cost and operational optimization strategies. The broad experiences from all of the experts included and scope of the biobanks they represent should provide a level of relevant representation for all interested parties.

  14. 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.

  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. 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.

  17. Growth control of Listeria monocytogenes on cold-smoked salmon using a competitive lactic acid bacteria flora.

    Science.gov (United States)

    Nilsson, L; Gram, L; Huss, H H

    1999-04-01

    A Lactobacillus sake strain LKE5 and four strains of Carnobacterium piscicola were evaluated as biopreservation cultures to control the growth of Listeria monocytogenes on vacuum-packed, cold-smoked salmon stored at 5 degrees C. All five strains were antilisterial as live cultures in an agar diffusion assay. Cell-free supernatants of two strains of C. piscicola and L. sake LKE5 were also antilisterial because of the production of bacteriocins. The presence of high cell numbers of strains of C. piscicola had no influence on the sensory quality of cold-smoked salmon stored at 5 degrees C, but L. sake LKE5 caused strong sulfurous off-flavors and was rejected as a culture for biopreservation of cold-smoked salmon. A bacteriocin-producing strain of C. piscicola (A9b) initially caused a 7-day lag phase of L. monocytogenes, followed by a reduction in numbers of L. monocytogenes from 10(3) CFU/ml to below 10 CFU/ml after 32 days of incubation, coinciding with the detection of antilisterial compounds. The presence of a nonbacteriocin-producing strain of C. piscicola (A10a) prevented the growth of L. monocytogenes during the 32-day incubation. The growth of L. monocytogenes was strongly repressed on cold-smoked salmon in the presence of C. piscicola A9b and A 10a, respectively. The initial cell numbers of L. monocytogenes that were found on Oxford plates incubated at 25 degrees C reached low maximum cell counts of 10(4) and 2 x 10(3) after 14 and 20 days of storage in mixed culture with C. piscicola A9b and A10a.

  18. Engineered Trehalose Permeable to Mammalian Cells.

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    Alireza Abazari

    Full Text Available Trehalose is a naturally occurring disaccharide which is associated with extraordinary stress-tolerance capacity in certain species of unicellular and multicellular organisms. In mammalian cells, presence of intra- and extracellular trehalose has been shown to confer improved tolerance against freezing and desiccation. Since mammalian cells do not synthesize nor import trehalose, the development of novel methods for efficient intracellular delivery of trehalose has been an ongoing investigation. Herein, we studied the membrane permeability of engineered lipophilic derivatives of trehalose. Trehalose conjugated with 6 acetyl groups (trehalose hexaacetate or 6-O-Ac-Tre demonstrated superior permeability in rat hepatocytes compared with regular trehalose, trehalose diacetate (2-O-Ac-Tre and trehalose tetraacetate (4-O-Ac-Tre. Once in the cell, intracellular esterases hydrolyzed the 6-O-Ac-Tre molecules, releasing free trehalose into the cytoplasm. The total concentration of intracellular trehalose (plus acetylated variants reached as high as 10 fold the extracellular concentration of 6-O-Ac-Tre, attaining concentrations suitable for applications in biopreservation. To describe this accumulation phenomenon, a diffusion-reaction model was proposed and the permeability and reaction kinetics of 6-O-Ac-Tre were determined by fitting to experimental data. Further studies suggested that the impact of the loading and the presence of intracellular trehalose on cellular viability and function were negligible. Engineering of trehalose chemical structure rather than manipulating the cell, is an innocuous, cell-friendly method for trehalose delivery, with demonstrated potential for trehalose loading in different types of cells and cell lines, and can facilitate the wide-spread application of trehalose as an intracellular protective agent in biopreservation studies.

  19. Elimination of Pathogen Escherichia coli O157:H7 in Ground Beef by a Newly Isolated Strain of Lactobacillus acidophilus during Storage at 5°C

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    Alireza Goodarzi

    2016-06-01

    Full Text Available Background and Objective: Constant use of limited number of lactic acid bacteria species in biopreservation can cause genetic degradation and or rising resistance against food pathogens or antimicrobial substances they produce. For this objective, a newly isolated strain of Lactobacillus acidophilus possessing high antimicrobial activity was evaluated as a candidate for use in biopreservation.Materials and Methods: Antibacterial activity was evaluated by agar disk diffusion method. Hydrogen peroxide amount was measured by Merckoquant Peroxide test strips. Microbiological analysis of the ground beef infected by Escherichia coli O157:H7 and treated by Lactobacillus acidophilus GH 201was done by plating of serial dilution in physiological saline on Tryptose agar.Results and Conclusion: The cells (109 CFU ml-1 of Lactobacillus acidophilus produced significant amount of antibacterial substances mainly hydrogen peroxide (28 and 30 μg ml-1 in sodium phosphate buffer (0.2 M, pH 6.5 and LAPTg at 5°C during submerged cultivation with no growth, respectively. Submerged co-cultivation of Escherichia coli O157:H7 with lactobacilli in LAPTg broth at 5°C reduced the total number of the pathogen more than 2 log for 5 days. In case of solid state cultivation on agar-based medium, the maximum inhibitory zones on Escherichia coli O157:H7 lawn around the disks soaked by different amounts of washed Lactobacillus acidophilus cells appear for one-day cold exposition. The size of inhibition zone depends on the concentration of lactic acid bacteria cells. The cell suspension intended for treatment must contain 108-9CFU ml-1 of lactic acid bacteria. Lactobacillus acidophilus reduced the initial amount (2×105 CFU ml-1 of Escherichia coli O157:H7 in ground beef up to 2 log for 5 days of solid-state co-cultivation. The application of Lactobacillus acidophilus bacteria expanded the shelf-life of ground beef due to inhibition of

  20. 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.

  1. Probiotic properties of endemic strains of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Flora N. Tkhruni

    2013-01-01

    Full Text Available Strains of lactic acid bacteria (LAB isolated from various samples of matsun, yogurt and salted cheese from natural farms of Armenia were studied. They have high antimicrobial and probiotic activities, growth rate and differ by their resistance to enzymes. Supernatants of LAB retain bactericidal activity at рН 3.0-8.0 and inhibit growth of various microflora. The application of different methods of identification and LAB genotyping (API 50 CH, 16S rRNA sequencing, GS-PCR, RAPD PCR showed that isolated LAB evidenced a 99.9% similarity with L. rhamnosus, L. plantarum and L. pentosus species and coccoid forms of Streptococcus and Enterococcus species. It can be concluded, that some strains of lactic acid bacteria, isolated from dairy products from natural farms of Armenia, can be properly used for biopreservation of some foodstuffs. On the basis of experimental data, the LAB can be used as basis for obtaining the new products of functional nutrition.

  2. Bioprotective potential of lactic acid bacteria in malting and brewing.

    Science.gov (United States)

    Rouse, Susan; van Sinderen, Douwe

    2008-08-01

    Lactic acid bacteria (LAB) are naturally associated with many foods or their raw ingredients and are popularly used in food fermentation to enhance the sensory, aromatic, and textural properties of food. These microorganisms are well recognized for their biopreservative properties, which are achieved through the production of antimicrobial compounds such as lactic acid, diacetyl, bacteriocins, and other metabolites. The antifungal activity of certain LAB is less well characterized, but organic acids, as yet uncharacterized proteinaceous compounds, and cyclic dipeptides can inhibit the growth of some fungi. A variety of microbes are carried on raw materials used in beer brewing, rendering the process susceptible to contamination and often resulting in spoilage or inferior quality of the finished product. The application of antimicrobial-producing LAB at various points in the malting and brewing process could help to negate this problem, providing an added hurdle for spoilage organisms to overcome and leading to the production of a higher quality beer. This review outlines the bioprotective potential of LAB and its application with specific reference to the brewing industry.

  3. Application of Antimicrobial Agents Produced by Lactobacillus plantarum IIA-1A5 as Natural Preservative on Beef during Room Temperature Storage

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    Dewi Elfrida Sihombing

    2015-05-01

    Full Text Available Lactobacillus plantarum IIA-1A5 is indigenous lactic acid bacteria isolated from Indonesian beef. Lactobacillus plantarum IIA-1A5 was reported could produce bacteriocin, called plantaricin IIA-1A5. The aims of this research was to analyze application of plantaricin IIA-1A5 as a natural preservative on beef. Based on antagonistic test, plantaricin IIA-1A5 had good moderate antimicrobial activity against pathogenic bacteria isolated from human’s feces that cause diarrhea such as Salmonella 38, Enteropathogenic Escherichia coli K11 and Shigella A33. Application of plantaricin IIA-1A5 was effective as a natural preservative on beef stored at room temperature by inhibiting the growth of Escherichia coli and Staphylococcus aureus. Plantaricin IIA-1A5 could kill all of the Escherichia coli after 5 h storage. Plantaricin IIA-1A5 could reduce the population of Staphylococcus aureus in beef during room temperature storage. Interestingly, plantaricin produced by Lactobacillus plantarum IIA-1A5 was effective against gram negative and positive bacteria. According to physichochemichal and microbiology quality, plantaricin IIA-1A5 was recommended as biopreservative agents for beef.

  4. Lactic acid bacteria as a cell factory for the delivery of functional biomolecules and ingredients in cereal-based beverages: a review.

    Science.gov (United States)

    Waters, Deborah M; Mauch, Alexander; Coffey, Aidan; Arendt, Elke K; Zannini, Emanuele

    2015-01-01

    In this review, we aim to describe the mechanisms by which LAB can fulfil the novel role of efficient cell factory for the production of functional biomolecules and food ingredients to enhance the quality of cereal-based beverages. LAB fermentation is a safe, economical, and traditional method of food preservation foremost, as well as having the additional benefits of flavor, texture, and nutrition amelioration. Additionally, LAB fermentation in known to render cereal-based foods and beverages safe, in a chemical-free, consumer-friendly manner, from an antinutrient and toxigenic perspective. Huge market opportunities and potential exist for food manufacturers who can provide the ideal functional beverage fulfilling consumer needs. Newly developed fermented cereal-based beverages must address markets globally including, high-nutrition markets (developing countries), lifestyle choice consumers (vegetarian, vegan, low-fat, low-salt, low-calorie), food-related non-communicable disease sufferers (cardiovascular disease, diabetes), and green label consumers (Western countries). To fulfil these recommendations, a suitable LAB starter culture and cereal-based raw materials must be developed. These strains would be suitable for the biopreservation of cereal beverages and, ideally, would be highly antifungal, anti-mycotoxigenic, mycotoxin-binding and proteolytic (neutralize toxic peptides and release flavor-contributing amino acids) with an ability to ferment cereals, whilst synthesizing oligosaccharides, thus presenting a major opportunity for the development of safe cereal-based prebiotic functional beverages to compete with and replace the existing dairy versions.

  5. Isolation and Characterization of Phenolic Compounds and Anthocyanins from Murta (Ugni molinae Turcz. Fruits. Assessment of Antioxidant and Antibacterial Activity

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    Maria Paula Junqueira-Gonçalves

    2015-03-01

    Full Text Available Berry fruit consumption has become important in the promotion of human health, mainly due to their phenolic compounds, which have been associated with protection against different pathologies, as well as antimicrobial and other biological activities. Consequently, there has been a growing interest in identifying natural antioxidants and antimicrobials from these plants. This study aimed to characterize the phenolic chemical composition and anthocyanin profile of murta (Ugni molinae Turcz. fruit, and to evaluate the antioxidant and antimicrobial activity of its extracts (ethanolic and methanolic. LC/MS of the ethanolic extracts showed the presence of three major compounds: caffeic acid 3-glu, quercetin-3-glu and quercetin, while in the methanolic acid extract they were cyanidin-3-glucoside, pelargonidin-3-arabinose and delphinidin-3-glucoside. The antioxidant activity of ethanolic extracts (DPPH· and ORAC assays was higher than that of methanol acid extracts or purified anthocynins. Furthermore, the methanol acid extract showed an inhibitory activity against the bacteria E. coli and S. typhi similar to that of standard antibiotics. The results suggest that the antioxidant activity of the ethanolic extract is regulated by the high content of phenolic compounds and the fruit’s characteristic color is due to the content of pelargonidin-3-arabinose and delphinidin-3-glucoside. The obtained results demonstrated the appreciable antioxidant and antibacterial activities, providing opportunities to explore murta extracts as biopreservatives.

  6. 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.

  7. Diversity in the antibacterial potential of probiotic cultures Bacillus licheniformis MCC2514 and Bacillus licheniformis MCC2512.

    Science.gov (United States)

    Shobharani, Papanna; Padmaja, Radhakrishnan J; Halami, Prakash M

    2015-01-01

    The aim of the present study was to investigate the characteristic diversity and stability of antimicrobial compounds produced by two probiotic strains of Bacillus licheniformis (MCC2514 and MCC2512). Antimicrobial compounds from the two strains notably varied, related to stability and potency. The inhibitory spectrum of B. licheniformis MCC2512 was higher than MCC2514, but, related to the effect on Micrococcus luteus ATCC9341, MCC2514 (LD50 = 450 AU ml(-1)) was more potent than MCC2512 (LD50 = 750 AU ml(-1)). The compounds were thermo-resistant and stable at a wide range of pH and exhibited considerable resistance to digestive enzymes and bile salts (anionic biological detergents), contributing to their appropriate application in various food systems. The isolate B. licheniformis MCC2512 gave a positive response to Bacillus subtilis-based biosensors BSF2470 and BS168.BS2, confirming the mode of action on the cell wall and subtilin-type, respectively. For B. licheniformis MCC2514, the mode of action was characterized by constructing B. subtilis reporters that interfered in five major biosynthetic pathways, i.e., biosynthesis of DNA, RNA, protein, the cell wall and fatty acids. B. licheniformis MCC2514 responded to the yvgS reporter, indicating it as an RNA synthesis inhibitor. Overall, the investigation reveals variability of the antimicrobial compounds from B. licheniformis of different origins and for their possible application as biopreservative agents.

  8. Food-associated lactic acid bacteria with antimicrobial potential from traditional Mexican foods.

    Science.gov (United States)

    Alvarado, C; García Almendárez, B E; Martin, S E; Regalado, C

    2006-01-01

    This work was conducted to identify indigenous LAB capable of antimicrobial activity, present in traditional Mexican-foods with potential as natural preservatives. A total of 27 artisan unlabeled Mexican products were evaluated, from which 94 LAB strains were isolated, and only 25 strains showed antimicrobial activity against at least one pathogen indicator microorganism. Most of the inhibitory activity showed by the isolated LAB strains was attributed to pH reduction by organic acids. Lactobacillus and Lactococcus strains were good acid producers, depending on the substrate, and may enhance the safety of food products. Cell free cultures of Leuconostoc mesenteroides CH210, and PT8 (from chorizo and pulque, respectively) reduced the number of viable cells of enteropathogenic E. coli in broth system. Lb. plantarum CC10 (from "madre" of vinegar) showed significant inhibitory effect against S. aureus 8943. E. faecium QPII (from panela cheese) produced a bacteriocin with wide anti-L. monocytogenes activity. Selected LAB from traditional Mexican foods showed good potential as bio-preservatives.

  9. Bacteriocinogenic potential and safety evaluation of non-starter Enterococcus faecium strains isolated from home made white brine cheese.

    Science.gov (United States)

    Favaro, Lorenzo; Basaglia, Marina; Casella, Sergio; Hue, Isabelle; Dousset, Xavier; Gombossy de Melo Franco, Bernadette Dora; Todorov, Svetoslav Dimitrov

    2014-04-01

    Four LAB strains, isolated from Bulgarian home made white brine cheese, were selected for their effective inhibition against Listeria monocytogenes. According to their biochemical and physiological characteristics, the strains were classified as members of Enterococcus genus, and then identified as Enterococcus faecium by 16S rDNA sequencing. Their bacteriocin production and inhibitory spectrum were evaluated together with the occurrence of several bacteriocin genes (entA, entB, entP, entL50B). Their virulence potential and safety was assessed both using PCR targeted to the genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for antibiotic resistance, gelatinase, lipase, DNAse and α- and β-haemolysis. The E. faecium strains harboured at least one enterocin gene while the occurrence of virulence, antibiotic resistance and biogenic amines genes was limited. Considering their strong antimicrobial activity against L. monocytogenes strains, the four E. faecium strains exhibited promising potential as bio-preservatives cultures for fermented food productions.

  10. Effect of controlled lactic acid bacterial fermentation on the microbiological and chemical qualities of Moroccan sardines (Sardina pilchardus).

    Science.gov (United States)

    Ndaw, A; Zinedine, A; Faid, M; Bouseta, A

    2008-09-01

    Lactic acid bacteria (LAB) strains were assayed for the conservation of fresh sardine "Sardina pilchardus". Lactobacillus delbrueckii subsp. delbrueckii was used for inoculation of sardine fillets in a solution of NaCl (5%, w/w) and glucose (4%, w/w) concentration in water. Microbial counts including Standard Plate Count (SPC), LAB, yeasts, coliforms, Salmonella, staphylococci and Clostridium were followed during two weeks of storage at 30 degrees C. Determinations of chemical parameters including pH, dry matter, fat, ash, total nitrogen (NT), total volatile basic nitrogen (TVBN) and trimethylamine (TMA) were carried out under the same conditions. Chemical determinations showed a net pH decrease from an initial value of 6.05 in raw sardine fillets to 4.3 after 16 days of fermentation. Increases in TMA content and TBVN were observed. Microbiological control showed that LAB counts reached a level up to 3.10(9) cfu/g after 4 days of fermentation. After two weeks, fermented fish was free of coliforms and Salmonella. The inhibition of pathogenic microflora including staphylococci and Clostridium was also observed. The results indicated that controlled LAB fermentation could be used as a successful process for biopreservation of sardines produced in huge quantities in Morocco.

  11. Molecular characterization of lactobacilli isolated from fermented idli batter.

    Science.gov (United States)

    Agaliya, Perumal Jayaprabha; Jeevaratnam, Kadirvelu

    2013-12-01

    Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis.

  12. Inhibitory Effect of Lactococcin BZ Against Listeria innocua and Indigenous Microbiota of Fresh Beef.

    Science.gov (United States)

    Yıldırım, Zeliha; Yerlikaya, Sabire; Öncül, Nilgün; Sakin, Tuba

    2016-09-01

    In this study, the effect of lactococcin BZ on microbiological quality of fresh beef is investigated. For this purpose, the meat samples were treated with various amounts of lactococcin BZ (200-2500 AU/mL), a bacteriocin produced by Lactococcus lactis spp. lactis BZ, and kept at 4-5 °C for 12 days. During storage, the microbiological properties of the meat samples with or without lactococcin BZ were determined. Inhibitory effect of lactococcin BZ depended on its amount. The higher the amount of lactococcin BZ, the higher the inhibitory activity. Treatment with lactococcin BZ at the level of 2500 AU/mL resulted in 4.87, 3.50 and 3.94 log cycle decrease in the counts of mesophilic, psychrotrophic and lactic acid bacteria, respectively, and 1.90·10(4) and 1.04·10(2) CFU/g reduction in coliform and faecal coliform bacteria, respectively, at the end of storage as compared to their initial numbers in the control sample. However, the counts of these bacteria in control samples increased during storage. Also, lactococcin BZ at 1600 AU/mL showed very strong antilisterial effect against Listeria innocua in fresh meat and reduced the cell numbers from 6.04 log CFU/g to undetectable level on the 6th day of storage. In conclusion, lactococcin BZ has a potential use as a biopreservation agent to improve safety and shelf life of raw beef.

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

    Directory of Open Access Journals (Sweden)

    Danielle N. Furtado

    2015-03-01

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

  14. Antimicrobial activity and high thermostability of a novel BLIS secreted by Enterococcus Mundtii isolated from Lebanese cow’s milk

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    Imad AL Kassaa

    2016-12-01

    Full Text Available AL Kassaa, I., Safourim, N., Mostafa, N. and Hamze, M. Antimicrobial activity and high thermostability of a novel BLIS secreted by Enterococcus Mundtii isolated from lebanese cow’s milk. 2016. Lebanese Science Journal, 17(2: 166-176. Lactic acid bacteria (LAB are used in many fields such as fermentation agents, increasing nutritional value and improving organoleptic quality of food. Also they are used as probiotics and preservatives against pathogens and spoilage microbes by producing antimicrobial substances such as bacteriocins. Fifty cow’s milk samples were collected and 175 LAB isolates were isolated and identified by using biochemical method. Fifteen isolates showed an antimicrobial activity against Listeria monocytogenes ATCC® 19115™. One strain, BL4 which showed the strongest activity, was chosen to extract and characterize its antimicrobial substance in order to evaluate its potential use as a new food protective agent. This strain was identified as Enterococcus mundtii by pyrosequencing method. The active substance was extracted using solvent method. This Bacteriocin like Inhibitory Substances “BLIS” can support a high temperature (121 ˚C for a long time and resist pH variation. The BLIS BL4 can be considered as a peptide active against many food pathogen and food-spoilage microbes, such as Listeria monocytogenes and Penicillium spp. BLIS BL4 can be used in food application as bio-preservative to reduce food-spoilage and food-borne diseases in food products.

  15. Minimally Processed Functional Foods: Technological and Operational Pathways.

    Science.gov (United States)

    Rodgers, Svetlana

    2016-10-01

    This paper offers a concise review of technical and operational concepts underpinning commercialization of minimally processed functional foods (FFs), foods with fresh-like qualities commanding premium prices. The growing number of permitted nutritional content/health claims, many of which relate to well-being, coupled with emerging extraction and food processing technologies offers new exciting opportunities for small and medium size enterprises (SMEs) specializing in fresh produce to play an active role in the health market. Supporting SMEs, governments could benefit from savings in healthcare costs and value creation in the economy. Consumers could benefit from novel FF formats such as refrigerated RTE (ready-to-eat) meals, a variety of fresh-like meat-, fish-, and egg-based products, fresh-cut fruits and vegetables, cereal-based fermented foods and beverages. To preserve these valuable commodities, mild biological (enzymatic treatment, fermentation and, bio-preservation) and engineering solutions are needed. The latter include nonthermal techniques such as high-pressure treatment, cook-chill, sous-vide, mirco-encapsulation, vacuum impregnation and others. "De-constructive" culinary techniques such as 3D food printing and molecular gastronomy as well as developments in nutrigenomics and digital technologies facilitate novel product formats, personalization and access to niche markets. In the operational sense, moving from nourishment to health improvement demands a shift from defensive market-oriented to offensive market-developing strategies including collaborative networks with research organizations.

  16. Antimicrobial activity of the Nisin Z producer Lactococcus lactis subsp. lactis Lc08 against Listeria monocytogenes in skim milk

    Directory of Open Access Journals (Sweden)

    L.M. Perin

    2013-10-01

    Full Text Available The presented study aimed to verify the effect of different pH values, enzyme solutions and heat treatments on the antimicrobial activity of the bacteriocinogenic strain Lactococcus lactis subsp. lactis Lc08 and to test their antimicrobial activity against Listeria monocytogenes in reconstituted skim milk at refrigeration temperatures. This strain was previously described as a nisin Z producer and capable of inhibiting L. monocytogenes growth in in vitro tests. The antimicrobial activity of the bacteriocin cell-free supernatant of Lc08 was sensitive to enzyme treatments (except papain. The pH values and heating (65ºC for 30min, 75ºC for 15s had no apparent effect on the antimicrobial activity of the bacteriocin produced by Lc08. Only treatment at autoclave conditions result in loss of their antimicrobial activity. Lc08 presented antimicrobial activity against L. monocytogenes in the milk system after 12h at 25ºC. No effect was found at 7ºC. The results show the application viability of the Lc08 in food systems as a biopreservative against L. monocytogenes.

  17. Directed destabilization of lysozyme in protic ionic liquids reveals a compact, low energy, soluble, reversibly-unfolding (pre-fibril) state

    CERN Document Server

    Byrne, Nolene; Angell, C Austen

    2007-01-01

    Recent demonstrations of extraordinary stabilization of proteins in mobile protic [1] and aprotic [2] ionic liquid solutions at ambient temperatures have raised hopes of new biopreservation and drug transportation technologies. Here we examine the relation of folded protein stability to the state of the transferred proton [1], as determined by the N-H proton chemical shift, d(N-H). We identify a range of d(N-H) in which the unfolded lysozyme refolds 97%. Exceeding the stability range in the acid direction leads to the sudden formation and stabilization of a small, soluble, amyloid form of lysozyme which has its own stability range and which can again unfold/refold many times before an irreversible process, fibrillization, occurs. The tightly bound amyloid form of the lysozyme molecule, identified by circular dichroism spectra and dynamic light scattering, must be of very low energy since the unfolding process absorbs almost three times the enthalpy of normal lysozyme unfolding. alpha-lactalbumin shows similar...

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

    Directory of Open Access Journals (Sweden)

    Anastasiadou Sofia

    2009-01-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

  20. 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.

  1. Comparative Antifungal Effect of Lactic Acid Bacteria Strains on Penicillium digitatum

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    Adrian Matei

    2015-11-01

    Full Text Available Lactic acid bacteria (LAB are natural alternative to chemical preservatives for fruits. The aim of the research was to select LAB strains with high antifungal activity against Penicillium digitatum for the biopreservation of fruits. The antifungal activity of eight lactic acid bacteria strains has been evaluated against Penicilliuum digitatum isolated from orange, by overlay assay method and by optical microscope examination. The reversion of inhibition zone after 96 h was recorded as a fungistatic effect while those with inhibition zone for at least 7 days were recorded as fungicidal. The antifungal effect of efficient LAB strains was assessed by comparing inhibition of fungal biofilm formation in liquid media. The strains Lpl, Lpa, LAB 13, LAB 15, LAB 43 and LAB 58 presented intense antifungal activity with clear inhibition zones diameter over 20 mm. The microscopy evidenced atypical hyphae and delaying of conidial chain formation. The strains Lpa, LAB 13, LAB 15 fully inhibited the mycelia growth, strains LAB 43 and LAB 58 partly with delaying of biofilm formation on the surface of culture medium. The results of comparative antifungal activity of LAB strains evidenced the highest inhibition of fungal biofilm formation and structural damages of hyphae and spores caused by the strains Lpa, LAB 13 and LAB 15. These strains could be efficient biocontrol agents of Penicillium digitatum in fruits.

  2. Status, Antimicrobial Mechanism, and Regulation of Natural Preservatives in Livestock Food Systems

    Science.gov (United States)

    Lee, Na-Kyoung; Paik, Hyun-Dong

    2016-01-01

    This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use. PMID:27621697

  3. Status, Antimicrobial Mechanism, and Regulation of Natural Preservatives in Livestock Food Systems.

    Science.gov (United States)

    Lee, Na-Kyoung; Paik, Hyun-Dong

    2016-01-01

    This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use.

  4. Diffusion of Fluorescently Labeled Bacteriocin from Edible Nanomaterials and Embedded Nano-Bioactive Coatings.

    Science.gov (United States)

    Imran, Muhammad; Revol-Junelles, Anne-Marie; Francius, Grégory; Desobry, Stéphane

    2016-08-24

    Application of nano-biotechnology to improve the controlled release of drugs or functional agents is widely anticipated to transform the biomedical, pharmaceutical, and food safety trends. The purpose of the current study was to assess and compare the release rates of fluorescently labeled antimicrobial peptide nisin (lantibiotic/biopreservative) from liposomal nanocarriers. The elevated temperature, high electrostatic attraction between anionic bilayers and cationic nisin, larger size, and higher encapsulation efficiency resulted in rapid and elevated release through pore formation. However, acidic pH and optimal ethanol concentration in food simulating liquid (FSL) improved the stability and retention capacity of loaded drug. Thus, controlling various factors had provided partition coefficient K values from 0.23 to 8.78 indicating variation in nisin affinity toward encapsulating macromolecule or FSL. Interaction between nisin and nanoscale bilayer systems by atomic force (AFM) and transmission electron microscopy demonstrated membrane activity of nisin from adsorption and aggregation to pore formation. Novel nanoactive films with preloaded nanoliposomes embedded in biodegradable polymer revealed improved morphological, topographic, and roughness parameters studied by confocal microscopy and AFM. Pre-encapsulated nanoactive biopolymer demonstrated excellent retention capacity as drug carriers by decreasing the partition coefficient value from 1.8 to 0.66 (∼30%) due to improved stability of nanoliposomes embedded in biopolymer network.

  5. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Directory of Open Access Journals (Sweden)

    María José Grande Burgos

    2014-12-01

    Full Text Available Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria. The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure.

  6. Molecular characterization of lactobacilli isolated from fermented idli batter

    Directory of Open Access Journals (Sweden)

    Perumal Jayaprabha Agaliya

    2013-12-01

    Full Text Available Lactic acid bacteria are non pathogenic organism widely distributed in nature typically involved in a large number of spontaneous food fermentation. The purpose of this study was to characterize the bacteriocinogenic lactobacilli from fermented idli batter which can find application in biopreservation and biomedicine. Eight most promising lactobacilli were chosen from twenty two isolates based on their spectrum of activity against other lactic acid bacteria and pathogens. The eight lactobacilli were characterized based on the various classical phenotypic tests, physiological tests and biochemical tests including various carbohydrate utilization profiles. All isolates were homo fermentative, catalase, and gelatin negative. Molecular characterization was performed by RAPD, 16S rRNA analysis, 16S ARDRA, and Multiplex PCR for species identification. RAPD was carried out using the primer R2 and M13. Five different clusters were obtained based on RAPD indicating strain level variation. 16S rRNA analysis showed 99 to 100% homology towards Lactobacillus plantarum. The restriction digestion pattern was similar for all the isolates with the restriction enzyme AluI. The subspecies were identified by performing Multiplex PCR using species specific primer. Among the five clusters, three clusters were clearly identified as Lactobacillus plantarum subsp. plantarum, Lactobacillus pentosus, and Lactobacillus plantarum subsp. argentoratensis.

  7. 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.

  8. Probiotics: a comprehensive approach toward health foods.

    Science.gov (United States)

    Sharma, Monika; Devi, Mridula

    2014-01-01

    Food products containing probiotics and prebiotics are an important development in Health foods, which enhance health promoting microbial flora in the intestine. Probiotic refers to viable microorganism that promotes or support a beneficial balance of the autochthonous microbial population of the gastrointestinal tract. A number of genera of bacteria (and yeast) are used as probiotics, including Lactobacillus, Leuconostoc, Pediococcus, Bifidobacterium, Saccharomyces, and Enterococcus, but the main species believed to have probiotic characteristics are Lactobacillus acidophilus, Bifidobacterium spp., and L. casei. Probiotics can reduce diarrheal incidence, lactose intolerance, lower serum cholesterol, stimulate the immune system, control infections, act as antibiotics, suppress tumors, and protect against colon or bladder cancer by maintaining a healthy intestinal microflora balance. Lactic acid bacteria produce biopreservatives such as lactic acid, hydrogen peroxide, and bacteriocins that are used to retard both spoilage and the growth of pathogenic bacteria. Food, particularly dairy products are considered as an ideal vehicle for delivering probiotic bacteria to the human gastrointestinal tract. Cereals being rich source of prebiotics such as β-glucan and arabinoxylan, galacto-, and fructooligosaccharides are considered for development of probiotic foods. Good manufacturing practices must be applied in the manufacture of probiotic foods with quality assurance, and shelf-life conditions established.

  9. 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.

  10. 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.

  11. Effect of low temperature on stability of theta-type plasmids in Carnobacterium maltaromaticum.

    Science.gov (United States)

    Bohaychuk, Valerie M; van Belkum, Marco J; Stiles, Michael E; McMullen, Lynn M

    2008-03-01

    The heterologous production of useful peptides such as bacteriocins by lactic acid bacteria (LAB) has been studied for use in the biopreservation of foods. Recombinant plasmids can suffer drawbacks such as segregational instability affecting the production of these peptides in certain environments such as absence of selective pressure or low temperature. The link between growth temperature characteristics of parental strains and stability of theta-type plasmids at a low temperature was investigated. The growth of four parental strains at 4 degrees C and stability of five derivative theta-type plasmids transformed into Carnobacterium maltaromaticum UAL26 at 25 and 4 degrees C were determined. Two plasmids (pCD11 and pCaT) derived from psychrotrophic LAB and plasmid, pHW800, from Enterococcus faecium 226 with unknown growth temperature characteristics, had excellent stability when strains were grown at 4 degrees C. Plasmids (pTRKH2 and pUCB820) derived from LAB that did not grow at refrigeration temperatures were not stable at 4 degrees C. When a DNA fragment from pCD11 containing 22-bp repeats, a putative replication initiation site, and the gene for the RepA protein was inserted into pTRKH2, the resulting derivative plasmid was 100% stable at 4 degrees C.

  12. 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.

  13. Antifungal activity of two Lactobacillus strains with potential probiotic properties.

    Science.gov (United States)

    Gerbaldo, Gisela A; Barberis, Carla; Pascual, Liliana; Dalcero, Ana; Barberis, Lucila

    2012-07-01

    Aflatoxin (highly toxic and carcinogenic secondary metabolites produced by fungi) contamination is a serious problem worldwide. Modern agriculture and animal production systems need to use high-quality and mycotoxin-free feedstuffs. The use of microorganisms to preserve food has gained importance in recent years due to the demand for reduced use of chemical preservatives by consumers. Lactic acid bacteria are known to produce various antimicrobial compounds that are considered to be important in the biopreservation of food and feed. Lactobacillus rhamnosus L60 and Lactobacillus fermentum L23 are producers of secondary metabolites, such as organic acids, bacteriocins and, in the case of L60, hydrogen peroxide. The antifungal activity of lactobacilli strains was determined by coculture with Aspergillus section Flavi strains by two qualitative and one quantitative methods. Both L23 and L60 completely inhibited the fungal growth of all aflatoxicogenic strains assayed. Aflatoxin B (1) production was reduced 95.7-99.8% with L60 and 27.5-100% with L23. Statistical analysis of the data revealed the influence of L60 and L23 on growth parameters and aflatoxin B (1) production. These results are important given that these aflatoxicogenic fungi are natural contaminants of feed used for animal production, and could be effectively controlled by Lactobacillus L60 and L23 strains with probiotic properties.

  14. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    Science.gov (United States)

    Grande Burgos, María José; Pérez Pulido, Rubén; López Aguayo, María del Carmen; Gálvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This cationic peptide inserts into bacterial membranes and causes membrane permeabilization, leading ultimately to cell death. Microarray analysis revealed sets of up-regulated and down-regulated genes in Bacillus cereus cells treated with sublethal bacteriocin concentration. Enterocin AS-48 can be purified in two steps or prepared as lyophilized powder from cultures in whey-based substrates. The potential applications of enterocin AS-48 as a food biopreservative have been corroborated against foodborne pathogens and/or toxigenic bacteria (Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enterica) and spoilage bacteria (Alicyclobacillus acidoterrestris, Bacillus spp., Paenibacillus spp., Geobacillus stearothermophilus, Brochothrix thermosphacta, Staphylococcus carnosus, Lactobacillus sakei and other spoilage lactic acid bacteria). The efficacy of enterocin AS-48 in food systems increases greatly in combination with chemical preservatives, essential oils, phenolic compounds, and physico-chemical treatments such as sublethal heat, high-intensity pulsed-electric fields or high hydrostatic pressure. PMID:25493478

  15. 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.

  16. Spontaneous nisin-resistant Listeria monocytogenes mutants with increased expression of a putative penicillin-binding protein and their sensitivity to various antibiotics.

    Science.gov (United States)

    Gravesen, A; Sørensen, K; Aarestrup, F M; Knøchel, S

    2001-01-01

    A concern regarding the use of bacteriocins, as for example the lantibiotic nisin, for biopreservation of certain food products is the possibility of resistance development and potential cross-resistance to antibiotics in the target organism. The genetic basis for nisin resistance development is as yet unknown. We analyzed changes in gene expression following nisin resistance development in Listeria monocytogenes 412 by restriction fragment differential display. The mutant had increased expression of a protein with strong homology to the glycosyltransferase domain of high-molecular-weight penicillin-binding proteins (PBPs), a histidine protein kinase, a protein of unknown function, and ClpB (putative functions from homology). The three former proteins had increased expression in a total of six out of 10 independent mutants originating from five different wild-type strains, indicating a prevalent nisin resistance mechanism under the employed isolation conditions. Increased expression of the putative PBP may affect the cell wall composition and thereby alter the sensitivity to cell wall-targeting compounds. The mutants had an isolate-specific increase in sensitivity to different beta-lactams and a slight decrease in sensitivity to another lantibiotic, mersacidin. A model incorporating these observations is proposed based on current knowledge of nisin's mode of action.

  17. 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.

  18. Inhibitory Effect of Lactococcin BZ Against Listeria innocua and Indigenous Microbiota of Fresh Beef

    Science.gov (United States)

    Yerlikaya, Sabire; Öncül, Nilgün; Sakin, Tuba

    2016-01-01

    Summary In this study, the effect of lactococcin BZ on microbiological quality of fresh beef is investigated. For this purpose, the meat samples were treated with various amounts of lactococcin BZ (200–2500 AU/mL), a bacteriocin produced by Lactococcus lactis spp. lactis BZ, and kept at 4–5 °C for 12 days. During storage, the microbiological properties of the meat samples with or without lactococcin BZ were determined. Inhibitory effect of lactococcin BZ depended on its amount. The higher the amount of lactococcin BZ, the higher the inhibitory activity. Treatment with lactococcin BZ at the level of 2500 AU/mL resulted in 4.87, 3.50 and 3.94 log cycle decrease in the counts of mesophilic, psychrotrophic and lactic acid bacteria, respectively, and 1.90·104 and 1.04·102 CFU/g reduction in coliform and faecal coliform bacteria, respectively, at the end of storage as compared to their initial numbers in the control sample. However, the counts of these bacteria in control samples increased during storage. Also, lactococcin BZ at 1600 AU/mL showed very strong antilisterial effect against Listeria innocua in fresh meat and reduced the cell numbers from 6.04 log CFU/g to undetectable level on the 6th day of storage. In conclusion, lactococcin BZ has a potential use as a biopreservation agent to improve safety and shelf life of raw beef. PMID:27956863

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

    Science.gov (United States)

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

    2015-03-01

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

  20. 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.

  1. 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.

  2. Inhibition of Listeria monocytogenes in cold-smoked salmon by Carnobacterium piscicola CS526 isolated from frozen surimi.

    Science.gov (United States)

    Yamazaki, Koji; Suzuki, Minako; Kawai, Yuji; Inoue, Norio; Montville, Thomas J

    2003-08-01

    Strain CS526 was isolated from frozen surimi and identified as a bacteriocin producer that had strong inhibitory activity against Listeria monocytogenes. Strain CS526 was identified as Carnobacterium piscicola by partial 16S rDNA sequence similarity. The ability of this bacteriocinogenic strain and nonbacteriocinogenic C. piscicola JCM5348 to inhibit the growth of L. monocytogenes was examined in culture broth incubated at 12 degrees C and cold-smoked salmon stored at 4, 12, and 20 degrees C. L. monocytogenes viable counts in the culture broth rapidly declined from 10(6) colony-forming units per ml to less than 10 colony-forming units per ml within 1 day at 12 degrees C in the presence of C. piscicola CS526. At 4 and 12 degrees C, inhibition of L. monocytogenes on salmon depended on the initial inoculum level of C. piscicola CS526. However, C. piscicola CS526 was bactericidal to L. monocytogenes within 21 and 12 days at 4 and 12 degrees C in cold-smoked salmon, respectively, even when the initial inoculum levels were low. C. piscicola CS526 suppressed the maximum cell number of L. monocytogenes by two and three log cycles, even at 20 degrees C. However, C. piscicola JCM5348 did not prevent the growth of the pathogen, except at 4 degrees C. Bacteriocin was detected in the samples coinoculated with C. piscicola CS526. The study shows that C. piscicola CS526 might have potential for biopreservation of refrigerated foods against L. monocytogenes.

  3. Genetic diversity and some aspects of antimicrobial activity of lactic acid bacteria isolated from goat milk.

    Science.gov (United States)

    Cavicchioli, Valéria Quintana; Dornellas, Wesley Dos Santos; Perin, Luana Martins; Pieri, Fábio Alessandro; Franco, Bernadette Dora Gombossy de Melo; Todorov, Svetoslav Dimitrov; Nero, Luís Augusto

    2015-03-01

    Lactic acid bacteria (LAB, n = 57) were previously obtained from raw goat milk, identified as Lactococcus spp. (n = 24) and Enterococcus spp. (n = 33), and characterized as bacteriocinogenic. Fingerprinting by pulsed field gel electrophoresis (PFGE) demonstrated high genetic diversity, and 30 strains were selected and exhibited strong antimicrobial activity against 46 target strains (LAB, spoilage, and foodborne pathogens). Six strains (Lactococcus lactis: GLc03 and GLc05; and Enterococcus durans: GEn09, GEn12, GEn14, and GEn17) were selected to characterize their bacteriocinogenic features, using Listeria monocytogenes ATCC 7644 as the target. The six strains produced bacteriocins at higher titer when incubated in MRS at 37 °C up to 12 h, when compared to growth at 25 and 30 °C. The produced bacteriocins kept their antimicrobial activity after exposure to 100 °C for 2 h and 121 °C for 20 min; the antimicrobial activity was also observed after treatment at pH 2.0 to 10.0, except for GLc03. L. monocytogenes populations were reduced approximately two logs after treatment with cell-free supernatants from the selected strains. These data show that goat milk can contain a diverse microbiota able to inhibit L. monocytogenes, a common pathogen found in dairy products, and can be potentially employed in biopreservation of food produced under different processing conditions.

  4. Evidence for probiotic potential of a capsular-producing Streptococcus thermophilus CHCC 3534 strain.

    Science.gov (United States)

    Khalil, Rowaida

    2009-01-01

    The purpose of this research was to evaluate the probiotic potential of an capsulated Streptococcus thermophilus CHCC 3534 strain. The strain tolerates 0.4% oxgall (bile) and was sufficiently resistant to pH as low as 2.5 for 3 hours of exposure. The strain demonstrated high adherence to human intestinal mucus, and showed unique resistance to different antibiotics. Crude extracts ofS. thermophilus CHCC 3534 contained a diffusible antimicrobial compound "bacteriocin" with a broad spectrum that inhibited the growth of closely related lactic acid bacteria and a number of food spoilage bacteria including Salmonella typhimurium and Staphylococcus aureus. The bacteriocin was heat stable, resistant to pH, inactivated by proteolytic enzymes, and resistant to a-amylase and lipase. A SDS-PAGE analysis of the partially purified bacteriocin revealed one component with a molecular weight ranging from 14.4 to 18.4 kDa. The strain may have industrial significance and represents an interesting candidate for use in biopreservation, probiotic food formulations and in the control of spoilage caused by food borne pathogens.

  5. Diversity of bacteriocinogenic lactic acid bacteria isolated from Mediterranean fish viscera.

    Science.gov (United States)

    Migaw, Sarra; Ghrairi, Taoufik; Belguesmia, Yanath; Choiset, Yvan; Berjeaud, Jean-Marc; Chobert, Jean-Marc; Hani, Khaled; Haertlé, Thomas

    2014-04-01

    Nine lactic acid bacteria strains showing bacteriocin-like activity were isolated from various fresh fish viscera. The following species were identified based on 16S rDNA sequences: Enterococcus durans (7 isolates), Lactococcus lactis (1) and Enterococcus faecium (1). These strains were active against Listeria innocua and other LAB. Random amplified polymorphic DNA analyses showed four major patterns for the E. durans species. PCR analyses revealed a nisin gene in the genome of the Lc. lactis strain. Genes coding enterocins A, B and P were found in the genome of the E. faecium isolate. Enterocins A and B genes were also present in the genome of E. durans GM19. Hence, this is the first report describing E. durans strains producing enterocins A and B. Electrospray ionization mass spectrometry revealed that the purified bacteriocin produced by the E. durans GMT18 strain had an exact molecular mass of 6,316.89 Da. This bacteriocin was designated as durancin GMT18. Edman sequencing failed to proceed; suggesting that durancin GTM18 may contain terminal lanthionine residues. Overall, the results obtained revealed the presence of a variety of enterococci in Mediterranean fish viscera, as evidenced by their genetic profiles and abilities to produce different bacteriocins. These strains could be useful for food biopreservation or as probiotics.

  6. Inhibition of Listeria monocytogenes by Carnobacterium spp. strains in a simulated cold smoked fish system stored at 4 degrees C.

    Science.gov (United States)

    Duffes, F; Leroi, F; Boyaval, P; Dousset, X

    1999-03-01

    Preservation of smoked salmon from bacterial spoilage, and especially from Listeria monocytogenes by bacteriocin producers is a promising challenge. Over a hundred lactic acid bacteria, isolated from commercial vacuum packaged cold smoked salmon, were screened for their antagonistic activity against L. innocua. Twenty-two strains were able to produce bacteriocin-like proteinaceous substances. These strains were characterized physiologically and biochemically as Carnobacterium strains. Three different groups were determined by pulsed-field gel electrophoresis after Sma I and Apa I DNA digestion. Peptidoglycan hydrolases patterns completed the characterization of these strains. All were confirmed as being Carnobacterium piscicola. Growth and bacteriocin production of three strains of each group and two well known bacteriocin producers (C. divergens V41 and C. piscicola V1) were tested in a simulated cold smoked fish system at 4 degrees C. These strains were able to reach 10(8) cfu ml(-1) in 21 days and to produce as much bacteriocin activities in the cold smoked fish system as in the rich media. Carnobacterium divergens V41 and C. piscicola V1 were the most effective strains in co-culture experiments, inhibiting L. monocytogenes as early as day 4, whereas C. piscicola SF668 inhibiting effect was observed at day 13. The potential for using such biopreservation treatments on whole smoked salmon is discussed.

  7. 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.

  8. Restriction fragment differential display of pediocin-resistant Listeria monocytogenes 412 mutants shows consistent overexpression of a putative beta-glucoside-specific PTS system.

    Science.gov (United States)

    Gravesen, A; Warthoe, P; Knochel, S; Thirstrup, K

    2000-06-01

    Pediocin PA-1, which is a bacteriocin produced by lactic acid bacteria, has potential as a biopreservative of food. However, such use may lead to the development of resistance in the target organism. Gene expression in two independent pediocin-resistant mutants of Listeria monocytogenes 412 was compared to the original isolate by restriction fragment differential display PCR (RFDD-PCR). This method amplifies cDNA restriction fragments under stringent PCR conditions, enabled by the use of specific primers complementary to ligated adaptor sequences. RFDD-PCR was very well suited for analysis of listerial gene expression, giving reproducible PCR product profiles. Three gene fragments having increased expression in both resistant mutants were identified. All three had homology to components of beta-glucoside-specific phosphoenolpyruvate-dependent phosphotransferase systems (PTS), one fragment having homology to enzyme II permeases, and the two others to phospho-beta-glucosidases. Overexpression of the putative PTS system was consistently observed in 10 additional pediocin-resistant mutants, isolated at different pH, salt content and temperature. The results suggest that RFDD-PCR is a strong approach for the analysis of prokaryotic gene expression and that the putative beta-glucoside-specific PTS system is involved in mediating pediocin resistance.

  9. 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Nivedita Sharma

    2014-09-01

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

  12. 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.

  13. 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.

  14. 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

  15. Study of the Antimicrobial and Probiotic Effect of Lactobacillus Plantarum Isolated from Raw Goat's Milk from the Region of Western Algeria

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    Mami anas

    2014-05-01

    Full Text Available The evolution from a spontaneous fermentation to a directed one is realised with selected lactic starters which give many dairy products processing various organoleptic characters. The integration of new lactic acid bacteria strains isolated from diverse ecosystems is now used to increase the duration of bio-preservation of dairy products. Moreover, some lactic acid bacteria probiotic activity is exploited to produce functional food. The aim of this study is the research of the possible probiotic and technological potential with some preventive and therapeutic characteristics of some Lactobacillus species isolated from Algerian’s raw goat’s milk. The selected isolate was identify to species level as Lactobacillus plantarum (P6 using API 50CH Kits. Microbiological and biotechnological techniques are used to fulfill this work. Results obtained have shown that Lactobacillus plantarum (P6 can resist to acidic, basic and enzymatic stresses. So the former strain can be considered as a probiotic. Moreover, the inhibition activity of the Lactobacillus plantarum (P6 against pathogens strains (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25921, Bacillus cereus, Pseudomonas aeruginosa, Vibrio cholerae, Listeria ivanovii ATCC 19119 and Salmonella enterica is clearly obtained by testing these strains with the direct method. Finely, raw goat’s milk can be defined as an ecosystem that promotes the development of a microflora with probiotic characters.

  16. Control of household mycoflora in fermented sausages using phenolic fractions from olive mill wastewaters.

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    Chaves-López, Clemencia; Serio, Annalisa; Mazzarrino, Giovanni; Martuscelli, Maria; Scarpone, Emidio; Paparella, Antonello

    2015-08-17

    Biopreservation using polyphenols represents an alternative to chemical molecules for improving food safety. In this work, we evaluated the antifungal activity of polyphenols extracted from olive mill wastewater (OMWWP) to reduce or eliminate the growth of undesired fungi on the surface of dry fermented sausages. Antagonism against Penicillium expansum DSMZ 1282, Penicillium verrucosum DSMZ 12639, Penicillium nalgiovense MS01, Aspergillus ochraceus DSMZ 63304, Cladosporium cladosporioides MS12, and Eurotium amstelodami MS10 was evident at 1.25% OMWWP in vitro, whereas in situ application of 2.5% OMWWP strongly reduced undesired household fungal species such as C. cladosporioides, Penicillium aurantiogriseum, Penicillium commune, and Eurotium amstelodami, while a moderate antagonistic activity towards P. nalgiovense and Penicillium chrysogenum was observed at the same concentration. OMWWP at the concentrations used in this study demonstrated species-dependent antifungal activity by inhibiting both fungal growth and spore germination. Therefore, OMWWP can be regarded as a potential alternative to synthetic antifungal compounds to preserve the product from both oxidation and undesired fungi, without changing the sensory characteristics.

  17. Recent Advances in Food Processing Using High Hydrostatic Pressure Technology.

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    Wang, Chung-Yi; Huang, Hsiao-Wen; Hsu, Chiao-Ping; Yang, Binghuei Barry

    2016-01-01

    High hydrostatic pressure is an emerging non-thermal technology that can achieve the same standards of food safety as those of heat pasteurization and meet consumer requirements for fresher tasting, minimally processed foods. Applying high-pressure processing can inactivate pathogenic and spoilage microorganisms and enzymes, as well as modify structures with little or no effects on the nutritional and sensory quality of foods. The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have approved the use of high-pressure processing (HPP), which is a reliable technological alternative to conventional heat pasteurization in food-processing procedures. This paper presents the current applications of HPP in processing fruits, vegetables, meats, seafood, dairy, and egg products; such applications include the combination of pressure and biopreservation to generate specific characteristics in certain products. In addition, this paper describes recent findings on the microbiological, chemical, and molecular aspects of HPP technology used in commercial and research applications.

  18. Airtight storage of moist wheat grain improves bioethanol yields

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    Piens Kathleen

    2009-08-01

    Full Text Available Abstract Background Drying is currently the most frequently used conservation method for cereal grain, which in temperate climates consumes a major part of process energy. Airtight storage of moist feed grain using the biocontrol yeast Pichia anomala as biopreservation agent can substantially reduce the process energy for grain storage. In this study we tested the potential of moist stored grain for bioethanol production. Results The ethanol yield from moist wheat was enhanced by 14% compared with the control obtained from traditionally (dry stored grain. This enhancement was observed independently of whether or not P. anomala was added to the storage system, indicating that P. anomala does not impair ethanol fermentation. Starch and sugar analyses showed that during pre-treatment the starch of moist grain was better degraded by amylase treatment than that of the dry grain. Additional pre-treatment with cellulose and hemicellulose-degrading enzymes did not further increase the total ethanol yield. Sugar analysis after this pre-treatment showed an increased release of sugars not fermentable by Saccharomyces cerevisiae. Conclusion The ethanol yield from wheat grain is increased by airtight storage of moist grain, which in addition can save substantial amounts of energy used for drying the grain. This provides a new opportunity to increase the sustainability of bioethanol production.

  19. A novel enterocin T1 with anti-Pseudomonas activity produced by Enterococcus faecium T1 from Chinese Tibet cheese.

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    Liu, Hui; Zhang, Lanwei; Yi, Huaxi; Han, Xue; Gao, Wei; Chi, Chunliang; Song, Wei; Li, Haiying; Liu, Chunguang

    2016-02-01

    An enterocin-producing Enterococcus faecium T1 was isolated from Chinese Tibet cheese. The enterocin was purified by SP-Sepharose and reversed phase HPLC. It was identified as unique from other reported bacteriocins based on molecular weight (4629 Da) and amino acid compositions; therefore it was subsequently named enterocin T1. Enterocin T1 was stable at 80-100 °C and over a wide pH range, pH 3.0-10.0. Protease sensitivity was observed to trypsin, pepsin, papain, proteinase K, and pronase E. Importantly, enterocin T1 was observed to inhibit the growth of numerous Gram-negative and Gram-positive bacteria including Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes. Take together, these results suggest that enterocin T1 is a novel bacteriocin with the potential to be used as a bio-preservative to control Pseudomonas spp. in food.

  20. Chemoprevention by essential oil of turmeric leaves (Curcuma longa L.) on the growth of Aspergillus flavus and aflatoxin production.

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    Sindhu, S; Chempakam, B; Leela, N K; Suseela Bhai, R

    2011-05-01

    Turmeric is well known for a wide range of medicinal properties. Essential oil of turmeric leaves (Curcuma longa L.) were evaluated at varying concentrations of 0.01, 0.05, 0.1, 0.5, 0.75, 1.0 and 1.5% (v/v) in Yeast Extract Sucrose (YES) broth inoculated with spore suspension of Aspergillus flavus of 10(6)conidia/ml. These were evaluated for their potential in the control of aflatoxigenic fungus A. flavus and aflatoxin production. Turmeric leaf oil exhibited 95.3% and 100% inhibition of toxin production respectively at 1.0% and 1.5%. The extent of inhibition of fungal growth and aflatoxin production was dependent on the concentration of essential oil used. The oil exhibited significant inhibition of fungal growth as well as aflatoxins B(1) and G(1) production. The LD(50) and LD(90) were also determined. GC-MS analysis of the oil showed α-phellandrene, p-cymene and terpinolene as the major components in turmeric leaf oil. The possibility of using these phytochemical components as bio-preservatives for storage of spices is discussed.

  1. Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

    Science.gov (United States)

    Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

    2016-10-01

    Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.

  2. Antimicrobial effects of Turkish propolis, pollen, and laurel on spoilage and pathogenic food-related microorganisms.

    Science.gov (United States)

    Erkmen, Osman; Ozcan, Mehmet Musa

    2008-09-01

    The antimicrobial activities of propolis extract, pollen extract, and essential oil of laurel (Laurus nobilis L.) at concentrations from 0.02% to 2.5% (vol/vol) were investigated on bacteria (Bacillus cereus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Yersinia enterocolitica, Enterococcus faecalis, and Listeria monocytogenes), yeasts (Saccharomyces cerevisiae and Candida rugosa), and molds (Aspergillus niger and Rhizopus oryzae). Pollen has no antimicrobial effects on the bacteria and fungi tested in the concentrations used. Propolis showed a bactericidal effect at 0.02% on B. cereus and B. subtilis, at 1.0% on S. aureus and E. faecalis, and at 0.2% on L. monocytogenes. The minimum inhibitory concentration of propolis for fungi was 2.5%. Propolis and laurel were ineffective against E. coli and S. typhimurium at the concentrations tested. The results showed that the antimicrobial activity were concentration dependent. Propolis and essential oil of laurel may be used as biopreservative agents in food processing and preservation.

  3. Molecular Occurrence of Enterocin A Gene among Enterococcus faecium Strains Isolated from Gastro-Intestinal Tract and Antimicrobial Effect of this Bacteriocin Against Clinical Pathogens

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    Mitra Salehi

    2014-06-01

    Materials and Methods: In this study occurrence of class II enterocin structural gene (enterocin A in a target of 42 Enterococcus faecium strains, isolated from gastrointestinal tract of animal have been surveyed. E. faecium identification and occurrence of enterocin A gene was performed by PCR method. Cell-free neutralized supernatant of gene positive strains was used to test bacteriocin production and antimicrobial spectrum of supernatant was assayed by wall diffusion method on the gram-positive and negative indicators bacteriaResults: Based on our results, 73.8% of isolated strains had enterocin A gene that they inhibited growth of indicator bacteria such as clinical strain of Pseudomonas aeruginosa, Salmonella enteric PTCC1709, Listeria monocytogenes, Bacillus cereus and Bacillus subtilis.Conclusions: Studied enterocins have growth inhibitory spectrum on Gram-positive and Gram-negative bacteria especially against pathogenic bacteria in the gastrointestinal tract. Therefore, these strains have the potential to explore and use as, alternative antimicrobial compound and bio-preservatives in food or feed or as probiotics.

  4. Purification and characterization of antifungal compounds from Lactobacillus plantarum HD1 isolated from kimchi.

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    Ryu, Eun Hye; Yang, Eun Ju; Woo, Eun Rhan; Chang, Hae Choon

    2014-08-01

    Strain HD1 with antifungal activity was isolated from kimchi and identified as Lactobacillus plantarum. Antifungal compounds from Lb. plantarum HD1 were active against food- and feed-borne filamentous fungi and yeasts in a spot-on-the-lawn assay. Antifungal activity of Lb. plantarum HD1 was stronger against filamentous fungi than yeast. Antifungal compounds were purified using solid phase extraction (SPE) and recycling preparative-HPLC. Structures of the antifungal compounds were elucidated by electrospray ionization-mass spectrometry and nuclear magnetic resonance. Active compounds from Lb. plantarum HD1 were identified as 5-oxododecanoic acid (MW 214), 3-hydroxy decanoic acid (MW 188), and 3-hydroxy-5-dodecenoic acid (MW 214). To investigate the potential application of these antifungal compounds for reduction of fungal spoilage in foods, Korean draft rice wine was used as a food model. White film-forming yeasts were observed in control draft rice wine after 11 days of incubation. However, film-forming yeasts were not observed in draft rice wine treated with SPE-prepared culture supernatant of Lb. plantarum HD1 (equivalent to 2.5% addition of culture supernatant) until 27 days of incubation. The addition of antifungal compounds to Korean draft rice wine extended shelf-life up to 27 days at 10 °C without any sterilization process. Therefore, the antifungal activity of Lb. plantarum HD1 may lead to the development of powerful biopreservative systems capable of preventing food- and feed-borne fungal spoilage.

  5. Protein stability in stored decellularized heart valve scaffolds and diffusion kinetics of protective molecules.

    Science.gov (United States)

    Wang, Shangping; Oldenhof, Harriëtte; Dai, Xiaolei; Haverich, Axel; Hilfiker, Andres; Harder, Michael; Wolkers, Willem F

    2014-02-01

    Decellularized tissues can be used as matrix implants. The aims of this study were to investigate protein stability and solvent accessibility in decellularized pulmonary heart valve tissues. Protein denaturation profiles of tissues were studied by differential scanning calorimetry. Protein solvent accessibility of tissue exposed to D2O, and diffusion kinetics of various protective molecules were studied by Fourier transform infrared spectroscopy. Little changes were observed in the protein denaturation temperature during storage, at either 5 or 40°C. Glycerol was found to stabilize proteins; it increased the protein denaturation temperature. The stabilizing effect of glycerol disappeared after washing the sample with saline solution. Hydrogen-to-deuterium exchange rates of protein amide groups were fastest in leaflet tissue, followed by artery and muscle tissue. Diffusion of glycerol was found to be fastest in muscle tissue, followed by artery and leaflet tissue. Diffusion coefficients were derived and used to estimate the time needed to reach saturation. Fixation of tissue with glutaraldehyde had little effects on exchange and diffusion rates. Diffusion rates decreased with increasing molecular size. Proteins in decellularized heart valve tissue are stable during storage. Glycerol increases protein stability in a reversible manner. Solvent accessibility studies of protein amide groups provide an additional tool to study proteins in tissues. Diffusion coefficients can be derived to simulate diffusion kinetics of protective molecules in tissues. This study provides novel tools to evaluate protein stability and solvent accessibility in tissues, which can be used to develop biopreservation strategies.

  6. Preservation technologies for fresh meat - a review.

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    Zhou, G H; Xu, X L; Liu, Y

    2010-09-01

    Fresh meat is a highly perishable product due to its biological composition. Many interrelated factors influence the shelf life and freshness of meat such as holding temperature, atmospheric oxygen (O(2)), endogenous enzymes, moisture, light and most importantly, micro-organisms. With the increased demand for high quality, convenience, safety, fresh appearance and an extended shelf life in fresh meat products, alternative non-thermal preservation technologies such as high hydrostatic pressure, superchilling, natural biopreservatives and active packaging have been proposed and investigated. Whilst some of these technologies are efficient at inactivating the micro-organisms most commonly related to food-borne diseases, they are not effective against spores. To increase their efficacy against vegetative cells, a combination of several preservation technologies under the so-called hurdle concept has also been investigated. The objective of this review is to describe current methods and developing technologies for preserving fresh meat. The benefits of some new technologies and their industrial limitations is presented and discussed.

  7. Preservative Effect of Broad-Spectrum Enterocin LM-2 on Cold Sliced Ham%广谱乳酸菌细菌素enterocin LM-2对低温切片火腿的防腐保鲜效果(英文)

    Institute of Scientific and Technical Information of China (English)

    刘国荣; 王成涛; 王洋; 张宝; 李平兰

    2012-01-01

    为考察广谱乳酸菌细菌素enterocin LM-2对低温切片火腿的防腐保鲜效果,并探讨其在低温肉制品防腐保鲜中的应用可行性。本研究在不添加任何化学防腐剂的前提下,分别添加80、320、1280AU/g enterocin LM-2处理低温切片火腿,分析不同浓度细菌素处理前后样品中微生物数量、理化指标以及感官特性的变化。结果发现:细菌素enterocin LM-2的添加可明显延长低温切片火腿的货架期,有效减少贮藏过程中挥发性盐基氮的生成及脂肪氧化程度,并保持产品原有色泽、气味、质构等感官特性。综合微生物和理化特性分析结果,确定添加1280AU/g enterocin LM-2的处理组防腐效果最好,可将低温切片火腿的货架期延长至49d。这些结果都显示出乳酸菌细菌素enterocin LM-2有作为天然生物防腐剂应用于低温肉制品防腐保鲜中的巨大应用潜力。%Enterocin LM-2,a broad-spectrum bacteriocin isolated from Chinese traditional cheese,was produced by Enterococcus faecium LM-2.In order to examine the potential of enterocin LM-2 as a biopreservative in sliced cooked ham,the effect of enterocin LM-2 at different concentrations(80,320,1280 AU/g) on microbiological,physicochemical and sensory quality properties of sliced cooked ham during the refrigerated storage at 4 ℃ was explored in this paper.The addition of enterocin LM-2 could substantially suppress the growth of microflora,especially Listeria monocytogenes and Salmonella enteritidis,and decrease the accumulation of TVB-N and lipid oxidation during refrigerated storage of sliced cooked ham.Overall,the most effective treatment was achieved by adding 1280 AU/g enterocin LM-2,which could extend the shelf life up to 49 days and produce a better sensory profile during the whole storage period.These results clearly indicate that enterocin LM-2 has a great potential as a biopreservative for enhancing the safety and quality of refrigerated sliced cooked

  8. Qualitative detection of class IIa bacteriocinogenic lactic acid bacteria from traditional Chinese fermented food using a YGNGV-motif-based assay.

    Science.gov (United States)

    Liu, Wenli; Zhang, Lanwei; Yi, Huaxi; Shi, John; Xue, Chaohui; Li, Hongbo; Jiao, Yuehua; Shigwedha, Nditange; Du, Ming; Han, Xue

    2014-05-01

    In the present study, a YGNGV-motif-based assay was developed and applied. Given that there is an increasing demand for natural preservatives, we set out to obtain lactic acid bacteria (LAB) that produce bacteriocins against Gram-positive and Gram-negative bacteria. We here isolated 123 LAB strains from 5 types of traditional Chinese fermented food and screened them for the production of bacteriocins using the agar well diffusion assay (AWDA). Then, to acquire LAB producing class IIa bacteriocins, we used a YGNGV-motif-based assay that was based on 14 degenerate primers matching all class IIa bacteriocin-encoding genes currently deposited in NCBI. Eight of the LAB strains identified by AWDA could inhibit Gram-positive and Gram-negative bacteria; 5 of these were YGNGV-amplicon positive. Among these 5 isolates, amplicons from 2 strains (Y31 and Y33) matched class IIa bacteriocin genes. Strain Y31 demonstrated the highest inhibitory activity and the best match to a class IIa bacteriocin gene in NCBI, and was identified as Enterococcus faecium. The bacteriocin from Enterococcus avium Y33 was 100% identical to enterocin P. Both of these strains produced bacteriocins with strong antimicrobial activity against Listeria monocytogenes, Escherichia coli, and Bacillus subtilis, hence these bacteriocins hold promise as potential bio-preservatives in the food industry. These findings also indicated that the YGNGV-motif-based assay used in this study could identify novel class IIa bacteriocinogenic LAB, rapidly and specifically, saving time and labour by by-passing multiple separation and purification steps.

  9. Application of Lactobacillus amylovorus DSM19280 in gluten-free sourdough bread to improve the microbial shelf life.

    Science.gov (United States)

    Axel, Claudia; Röcker, Bettina; Brosnan, Brid; Zannini, Emanuele; Furey, Ambrose; Coffey, Aidan; Arendt, Elke K

    2015-05-01

    The present study investigated the antifungal activity of Lactobacillus amylovorus DSM19280 as a starter culture for gluten-free quinoa sourdough bread under pilot-plant conditions to extend the microbial shelf life. Challenge tests against environmental moulds were conducted and a negative control with non-antifungal strain, L. amylovorus DSM20531(T), as well as a chemically acidified and a non-acidified control were included. Organic acid production, antifungal metabolites, carbohydrates changes during fermentation and bread quality were compared to wheat counterparts. The application of quinoa sourdough fermented with the antifungal L. amylovorus DSM19280 extended the mould free shelf life by 4 days compared to the non-acidified control. No significant difference in lactic acid production was found between the lactobacilli strains. HPLC-UV/DAD was used to quantify antifungal compounds. The concentration of 4-hydroxyphenyllactic acid, phloretic acid, 3-phenyllactic acid and hydroferulic acid were significantly higher (P sourdough fermented with the antifungal L. amylovorus DSM19280 when compared to the non-antifungal strain, thus indicating their contribution to the antifungal activity. Evaluation of bread characteristics such as specific volume or crumb hardness, revealed that the addition of L. amylovorus fermented sourdough also improved bread quality. In conclusion, the combination of quinoa flour fermented with the antifungal L. amylovorus DSM19280 serves a great potential biopreservative ingredient to produce gluten-free breads with an improved nutritional value, better bread quality and higher safety due to an extended shelf life, and therefore meeting consumer needs for good quality and preservatives-free food products.

  10. Antilisterial activity of lactic acid bacteria isolated from vacuum-packaged brazilian meat and meat products Atividade antilisterial de bactérias láticas isoladas de carnes e produtos cárneos brasileiros embalados à vácuo

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    Elaine C.P. De Martinis

    2001-03-01

    Full Text Available Twenty samples of Brazilian meat and meat products were screened by the agar overlay method for bacteriocin-producing lactic acid bacteria, using Lactobacillus sake ATCC 15521 as indicator strain. Based on Gram staining, KOH reaction, catalase test and fermentation of 49 carbohydrates (API 50 CH, three out of seven isolates with confirmed antagonist properties were identified as Lactobacillus curvatus, one as Leuconostoc mesenteroides and one as Leuconostoc sp. Two isolates could not be properly identified using these tests. The inhibitors produced by these strains were sensitive to proteases. Inhibition due to lytic bacteriophages was ruled out, so the isolates were classified as bacteriocin-producing lactic acid bacteria. Four of them presented antilisterial activity and a potential application as biopreservatives in meat systems.Vinte amostras de carnes e produtos cárneos brasileiros foram analisadas com a finalidade de se isolar bactérias láticas produtoras de bacteriocina, através do método de antagonismo em ágar, utilizando Lactobacillus sake ATCC 15521 como microrganismo indicador. Baseado na coloração de Gram, reação com KOH, teste de catalase e teste de fermentação de 49 carboidratos (API 50 CH, três das sete cepas com características antagonísticas foram classificadas como Lactobacillus curvatus, uma como Leuconostoc mesenteroides e uma como Leuconostoc sp. Duas cepas não puderam ser identificadas usando apenas estes testes. Os inibidores produzidos por essas cepas mostraram-se sensíveis a proteases. A inibição devido a bacteriófagos líticos foi descartada e assim as culturas foram classificadas como bactérias láticas produtoras de bacteriocina. Quatro cepas apresentaram atividade antilisterial, e conseqüentemente um potencial de utilização como bioconservadores em produtos cárneos.

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

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    Darnawan Ari Nugroho

    2003-12-01

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

  12. Chemical Composition and Antimicrobial Activity of Essential Oils from Black Pepper, Cumin, Coriander and Cardamom Against Some Pathogenic Microorganisms

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    Teneva Desislava

    2016-12-01

    Full Text Available Four popular spices black pepper (Piper nigrum L., cumin (Cuminum cyminum L., coriander (Coriandrum sativum L. and cardamom (Elettaria cardamomum were analyzed for their oil composition by GC-MS. Thirty compounds were identified in the black pepper oil and the main components were β-caryophyllene (20.225 %, sabinene (18.054 %, limonene (16.924 %, α-pinene (9.171 % and α-phellandrene (5.968 %. Twenty five compounds were identified in the cumin oil – cuminaldehyde (30.834 %, 3-caren-10-al (17.223 %, β-pinene (14.837 %, γ–terpinene (11.928 %, 2-caren-10-al (8.228 % and pcymene (6.429 %. Twenty nine compounds were identified in the coriander oil – β-linalool (58.141 %, α-pinene (8.731 %, γ-terpinene (6.347 % and p-cymene (5.227 %. Twenty nine compounds were identified in the cardamom oil – α-terpinyl acetate (39.032 %, eucalyptol (31.534 %, β-linalool (4.829 %, sabinene (4.308 % and α-terpineol (4.127 %. The antimicrobial activity of essential oils against pathogenic (Escherichia coli ATCC 25922, Escherichia coli ATCC 8739, Salmonella sp. (clinical isolate, Staphylococcus aureus ATCC 6538P, Proteus vulgaris G microorganisms by disc-diffusion method was examined. Gram-positive bacteria were more sensitive to the oils (inhibition zones being between 8 and 12.5 mm and the minimum inhibitory concentration was more than 600 ppm; Gram-negative bacteria were less sensitive. The obtained essential oils are suitable for use as biopreservative agents.

  13. Primary metabolism in Lactobacillus sakei food isolates by proteomic analysis

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    Champomier-Vergès Marie-Christine

    2010-04-01

    Full Text Available Abstract Background Lactobacillus sakei is an important food-associated lactic acid bacterium commonly used as starter culture for industrial meat fermentation, and with great potential as a biopreservative in meat and fish products. Understanding the metabolic mechanisms underlying the growth performance of a strain to be used for food fermentations is important for obtaining high-quality and safe products. Proteomic analysis was used to study the primary metabolism in ten food isolates after growth on glucose and ribose, the main sugars available for L. sakei in meat and fish. Results Proteins, the expression of which varied depending on the carbon source were identified, such as a ribokinase and a D-ribose pyranase directly involved in ribose catabolism, and enzymes involved in the phosphoketolase and glycolytic pathways. Expression of enzymes involved in pyruvate and glycerol/glycerolipid metabolism were also affected by the change of carbon source. Interestingly, a commercial starter culture and a protective culture strain down-regulated the glycolytic pathway more efficiently than the rest of the strains when grown on ribose. The overall two-dimensional gel electrophoresis (2-DE protein expression pattern was similar for the different strains, though distinct differences were seen between the two subspecies (sakei and carnosus, and a variation of about 20% in the number of spots in the 2-DE gels was observed between strains. A strain isolated from fermented fish showed a higher expression of stress related proteins growing on both carbon sources. Conclusions It is obvious from the data obtained in this study that the proteomic approach efficiently identifies differentially expressed proteins caused by the change of carbon source. Despite the basic similarity in the strains metabolic routes when they ferment glucose and ribose, there were also interesting differences. From the application point of view, an understanding of regulatory

  14. Screening for antimicrobial and proteolytic activities of lactic acid bacteria isolated from cow, buffalo and goat milk and cheeses marketed in the southeast region of Brazil.

    Science.gov (United States)

    Tulini, Fabricio L; Hymery, Nolwenn; Haertlé, Thomas; Le Blay, Gwenaelle; De Martinis, Elaine C P

    2016-02-01

    Lactic acid bacteria (LAB) can be isolated from different sources such as milk and cheese, and the lipolytic, proteolytic and glycolytic enzymes of LAB are important in cheese preservation and in flavour production. Moreover, LAB produce several antimicrobial compounds which make these bacteria interesting for food biopreservation. These characteristics stimulate the search of new strains with technological potential. From 156 milk and cheese samples from cow, buffalo and goat, 815 isolates were obtained on selective agars for LAB. Pure cultures were evaluated for antimicrobial activities by agar antagonism tests and for proteolytic activity on milk proteins by cultivation on agar plates. The most proteolytic isolates were also tested by cultivation in skim milk followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the fermented milk. Among the 815 tested isolates, three of them identified as Streptococcus uberis (strains FT86, FT126 and FT190) were bacteriocin producers, whereas four other ones identified as Weissella confusa FT424, W. hellenica FT476, Leuconostoc citreum FT671 and Lactobacillus plantarum FT723 showed high antifungal activity in preliminary assays. Complementary analyses showed that the most antifungal strain was L. plantarum FT723 that inhibited Penicillium expansum in modified MRS agar (De Man, Rogosa, Sharpe, without acetate) and fermented milk model, however no inhibition was observed against Yarrowia lipolytica. The proteolytic capacities of three highly proteolytic isolates identified as Enterococcus faecalis (strains FT132 and FT522) and Lactobacillus paracasei FT700 were confirmed by SDS-PAGE, as visualized by the digestion of caseins and whey proteins (β-lactoglobulin and α-lactalbumin). These results suggest potential applications of these isolates or their activities (proteolytic activity or production of antimicrobials) in dairy foods production.

  15. Alternatives to overcoming bacterial resistances: State-of-the-art.

    Science.gov (United States)

    Rios, Alessandra C; Moutinho, Carla G; Pinto, Flávio C; Del Fiol, Fernando S; Jozala, Angela; Chaud, Marco V; Vila, Marta M D C; Teixeira, José A; Balcão, Victor M

    2016-10-01

    Worldwide, bacterial resistance to chemical antibiotics has reached such a high level that endangers public health. Presently, the adoption of alternative strategies that promote the elimination of resistant microbial strains from the environment is of utmost importance. This review discusses and analyses several (potential) alternative strategies to current chemical antibiotics. Bacteriophage (or phage) therapy, although not new, makes use of strictly lytic phage particles as an alternative, or a complement, in the antimicrobial treatment of bacterial infections. It is being rediscovered as a safe method, because these biological entities devoid of any metabolic machinery do not possess any affinity whatsoever to eukaryotic cells. Lysin therapy is also recognized as an innovative antimicrobial therapeutic option, since the topical administration of preparations containing purified recombinant lysins with amounts in the order of nanograms, in infections caused by Gram-positive bacteria, demonstrated a high therapeutic potential by causing immediate lysis of the target bacterial cells. Additionally, this therapy exhibits the potential to act synergistically when combined with certain chemical antibiotics already available on the market. Another potential alternative antimicrobial therapy is based on the use of antimicrobial peptides (AMPs), amphiphilic polypeptides that cause disruption of the bacterial membrane and can be used in the treatment of bacterial, fungal and viral infections, in the prevention of biofilm formation, and as antitumoral agents. Interestingly, bacteriocins are a common strategy of bacterial defense against other bacterial agents, eliminating the potential opponents of the former and increasing the number of available nutrients in the environment for their own growth. They can be applied in the food industry as biopreservatives and as probiotics, and also in fighting multi-resistant bacterial strains. The use of antibacterial antibodies

  16. Thymus Vulgaris (Red Thyme) and Caryophyllus Aromaticus (Clove) Essential Oils to Control Spoilage Microorganisms in Pork Under Modified Atmosphere

    Science.gov (United States)

    D’Amato, Serena; Mazzarrino, Giovanni; Rossi, Chiara; Serio, Annalisa; López, Clemencia Chaves; Celano, Gaetano Vitale; Paparella, Antonello

    2016-01-01

    In recent years, it has been confirmed that essential oils (EOs) exert antimicrobial activity as they are able to inhibit cell growth and inactivate microbial cells. The application of biopreservation strategies by means of EOs opens up interesting perspectives in the food industry, including meat production. The paper aims to evaluate the effects of Thymus vulgaris (red thyme) and Caryophyllus aromaticus (cloves) EOs on the development of the spoilage population of fresh pork packaged under modified atmosphere (MAP). In particular, the research was focused on Brochothrix thermosphacta, a specific spoilage microorganism of fresh meat packed in anaerobic conditions or under MAP. Amongst seven EOs, those that showed the highest antimicrobial activity on 5 B. thermosphacta strains in vitro were: cloves [minimum inhibitory concentration (MIC) 0.6-2.5 mg/mL], savory (MIC 2.5-5.0 mg/mL), and red thyme (MIC 2.5 to 20 mg/mL). Red thyme and cloves EOs were selected for meat treatment, by increasing the dose at 20 and 40 mg/mL respectively, to take into account the matrix effect that can reduce EO availability. In spite of the minor efficacy observed in vitro, 40 mg/mL red thyme EO strongly limited the growth of B. thermosphacta in pork samples up to day 6 of storage [below 3.0 Log colony forming unit (CFU)/g, starting from 2.0 Log CFU/g at time 0], and exerted an antimicrobial effect also on the aerobic mesophilic count. Good results were obtained also with 20 mg/mL red thyme EO. The control of B. thermosphacta growth through EOs encourages research on alternative methods for extending the shelf life of fresh meat under MAP. PMID:27853710

  17. Thymus vulgaris (red thyme and Caryophyllus aromaticus (clove essential oils to control spoilage microorganisms in pork under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Serena D'Amato

    2016-08-01

    Full Text Available In recent years, it has been confirmed that essential oils (EOs exert antimicrobial activity as they are able to inhibit cell growth and inactivate microbial cells. The application of biopreservation strategies by means of EOs opens up interesting perspectives in the food industry, including meat production. The paper aims to evaluate the effects of Thymus vulgaris (red thyme and Caryophyllus aromaticus (cloves EOs on the development of the spoilage population of fresh pork packaged under modified atmosphere (MAP. In particular, the research was focused on Brochothrix thermosphacta, a specific spoilage microorganism of fresh meat packed in anaerobic conditions or under MAP. Amongst seven EOs, those that showed the highest antimicrobial activity on 5 B. thermosphacta strains in vitro were: cloves [minimum inhibitory concentration (MIC 0.6-2.5 mg/mL], savory (MIC 2.5-5.0 mg/mL, and red thyme (MIC 2.5 to 20 mg/mL. Red thyme and cloves EOs were selected for meat treatment, by increasing the dose at 20 and 40 mg/mL respectively, to take into account the matrix effect that can reduce EO availability. In spite of the minor efficacy observed in vitro, 40 mg/mL red thyme EO strongly limited the growth of B. thermosphacta in pork samples up to day 6 of storage [below 3.0 Log colony forming unit (CFU/g, starting from 2.0 Log CFU/g at time 0], and exerted an antimicrobial effect also on the aerobic mesophilic count. Good results were obtained also with 20 mg/mL red thyme EO. The control of B. thermosphacta growth through EOs encourages research on alternative methods for extending the shelf life of fresh meat under MAP.

  18. “Life in Data”—Outcome of a Multi-Disciplinary, Interactive Biobanking Conference Session on Sample Data

    Science.gov (United States)

    Rabone, Muriel; Benson, Erica E.; Droege, Gabriele; Mackenzie-Dodds, Jackie; Lawlor, Rita T.

    2016-01-01

    Introduction: Clinical, biodiversity, and environmental biobanks share many data standards, but there is a lack of harmonization on how data are defined and used among biobank fields. This article reports the outcome of an interactive, multidisciplinary session at a meeting of the European, Middle Eastern, and African Society for Biopreservation and Biobanking (ESBB) designed to encourage a ‘learning-from-each-other’ approach to achieve consensus on data needs and data management across biobank communities. Materials, Methods, and Results: The Enviro-Bio and ESBBperanto Working Groups of the ESBB co-organized an interactive session at the 2013 conference (Verona, Italy), presenting data associated with biobanking processes, using examples from across different fields. One-hundred-sixty (160) diverse biobank participants were provided electronic voting devices with real-time screen display of responses to questions posed during the session. The importance of data standards and robust data management was recognized across the conference cohort, along with the need to raise awareness about these issues within and across different biobank sectors. Discussion and Conclusion: While interactive sessions require a commitment of time and resources, and must be carefully coordinated for consistency and continuity, they stimulate the audience to be pro-active and direct the course of the session. This effective method was used to gauge opinions about significant topics across different biobanking communities. The votes revealed the need to: (a) educate biobanks in the use of data management tools and standards, and (b) encourage a more cohesive approach for how data and samples are tracked, exchanged, and standardized across biobanking communities. Recommendations for future interactive sessions are presented based on lessons learned. PMID:26808538

  19. 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.

  20. 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.

  1. 广谱抗菌肽——片球菌素pediocin PA-1%Pediocin PA-1, a wide-spectrum bacteriocin from lactic acid bacteria

    Institute of Scientific and Technical Information of China (English)

    吕燕妮

    2011-01-01

    Pediocin PA-1 is a broad-spectrum lactic acid bacteria bacteriocin that shows a particularly strong activity against Listeria monocytogenes, a foodborne pathogen of special concern among the food industrys. This antimicrobial peptide is the most extensively studied class Ⅱa bacteriocin, and it has been sufficiently well characterized to be used as a food biopreservative. This review focuses on the progress that have been made in the elucidations of its structure and mode of action, includes an overview of its applications in food systems. In the future, protein engineering, genetic engineering and chemical synthesis may lead to the development of new antimicrobial peptides with improved properties, based on some features of the pediocin PA-1 molecule.%片球菌素PA-1是一种广谱的乳酸菌细菌素,它对食品工业中的腐败菌单核细胞增生李斯特氏菌有强烈的抑制作用,是Ⅱa类细菌素中研究最深入的一种抗菌肽,具有很好的作为食品生物防腐剂开发的应用前景。对近年来关于片球菌素PA-1的结构、作用方式及在食品中的应用作一综述,并对其未来的应用前景,在蛋白质工程、基因工程和化学合成方面进行性质改进做出了展望。

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Blaženka Kos

    2011-12-01

    Full Text Available Bacteriocins produced by probiotic strains effectively contribute to colonization ability of probiotic strains and facilitate their establishment in the competitive gut environment and also protect the gut from gastrointestinal pathogens. Moreover, bacteriocins have received considerable attention due to their potential application as biopreservatives, especially in dairy industry. Hence, the objective of this research was to investigate antimicrobial activity of probiotic strains Lactobacillus helveticus M92, Lactobacillus plantarum L4 and Enterococcus faecium L3, with special focus on their bacteriocinogenic activity directed towards representatives of the same or related bacterial species, and towards distant microorganisms including potential food contaminants or causative agents of gut infections. In order to induce bacteriocin production, probiotic cells were cocultivated with Lactococcus lactis subsp. lactis LMG 9450, one of the most important starter cultures in cheese production. The presence of bacteriocin coding genes was investigated by PCR amplification with sequence-specific primers for helveticin and was confirmed for probiotic strain L. helveticus M92. All examined probiotic strains have shown bacteriocinogenic activity against Staphylococcus aureus 3048, Staphylococcus aureus K-144, Escherichia coli 3014, Salmonella enterica serovar Typhimurium FP1, Bacillus subtilis ATCC 6633, Bacillus cereus TM2, which is an important functional treat of probiotic strains significant in competitive exclusion mechanism which provides selective advantage of probiotic strains against undesirable microorganisms in gastrointestinal tract of the host. According to obtained results, living cells of starter culture Lc. lactis subsp. lactis LMG 9450 induced bacteriocin production by examined probiotic strains but starter culture itself was not sensitive to bacteriocin activity.

  4. 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.

  5. Stability of enterocin AS-48 in fruit and vegetable juices.

    Science.gov (United States)

    Grande, Maria J; Lucas, Rosario; Valdivia, Eva; Abriouel, Hikmate; Maqueda, Mercedes; Omar, Nabil Ben; Martínez-Cañamero, Magdalena; Gálvezi, Antonio

    2005-10-01

    Enterocin AS-48 is a candidate bacteriocin for food biopreservation. Before addressing application of AS-48 to vegetable-based foods, the interaction between AS-48 and vegetable food components and the stability of AS-48 were studied. Enterocin AS-48 had variable interactions with fruit and vegetable juices, with complete, partial, or negligible loss of activity. For some juices, loss of activity was ameliorated by increasing the bacteriocin concentration, diluting the juice, or applying a heat pretreatment. In juices obtained from cabbage, cauliflower, lettuce, green beans, celery, and avocado, AS-48 was very stable for the first 24 to 48 h of storage under refrigeration, and decay of activity was markedly influenced by storage temperature. In fresh-made fruit juices (orange, apple, grapefruit, pear, pineapple, and kiwi) and juice mixtures, AS-48 was very stable for at least 15 days at 4 degrees C, and bacteriocin activity was still detectable after 30 days of storage. Gradual and variable loss of activity occurred in juices stored at 15 and 28 degrees C; inactivation was faster at higher temperatures. In commercial fruit juices (orange, apple, peach, and pineapple) stored at 4 degrees C, the bacteriocin was completely stable for up to 120 days, and over 60% of initial activity was still present in juices stored at 15 degrees C for the same period. Commercial fruit juices stored at 28 degrees C for 120 days retained between 31.5% (apple) and 67.71% (peach) of their initial bacteriocin activity. Solutions of AS-48 in sterile distilled water were stable (120 days at 4 to 28 degrees C). Limited loss of activity was observed after mixing AS-48 with some food-grade dyes and thickening agents. Enterocin AS-48 added to lettuce juice incubated at 15 degrees C reduced viable counts of Listeria monocytogenes CECT 4032 and Bacillus cereus LWL1 to below detection limits and markedly reduced viable counts of Staphylococcus aureus CECT 976.

  6. Growth of Carnobacterium divergens V41 and production of biogenic amines and divercin V41 in sterile cold-smoked salmon extract at varying temperatures, NaCl levels, and glucose concentrations.

    Science.gov (United States)

    Connil, Nathalie; Plissoneau, Léon; Onno, Bernard; Pilet, Marie-France; Prévost, Hervé; Dousset, Xavier

    2002-02-01

    A complete factorial design 2(3) was used to study some aspects of Carnobacterium divergens V41 metabolism (growth, biogenic amine production, and divercin V41 production) in sterile cold-smoked salmon extract (SSE) at varying temperatures (3 to 9 degrees C), NaCl levels (2.5 to 6.5%), and glucose concentrations (2 to 6 g liter(-1)). The results showed that temperature and NaCl content were the most influential factors on growth parameters in SSE. Predictive models are suggested for the assessment of C. divergens lag time (t(lag)) and maximum specific growth rate (micro(max)) Among the biogenic amines studied, only tyramine was found to be produced by C. divergens in SSE. Furthermore, we showed that temperature, NaCl, and glucose variations did not greatly affect tyramine and divercin V41 production by the bacteria under the experimental conditions used. Indeed, divercin V41, a bacteriocin from C. divergens V41 that is highly active against some Listeria strains, was produced in SSE even under harsh culture conditions. Similarly, tyramine production in SSE was delayed at 3 degrees C but reached 35 microg ml(-1) in all experiments after 27 days of storage. However, this final tyramine concentration in SSE is low compared with the threshold values of 100 to 800 microg g(-1) reported as the potentially toxic dose in foods. Thus, we have found that C. divergens V41 is a promising strain for the biopreservation of refrigerated cold-smoked salmon.

  7. Efficacy of enterocin AS-48 against bacilli in ready-to-eat vegetable soups and purees.

    Science.gov (United States)

    Grande, Maria J; Abriouel, Hikmate; Lucas López, Rosario; Valdivia, Eva; Ben Omar, Nabil; Martínez-Cañamero, Magdalena; Gálvez, Antonio

    2007-10-01

    The broad-spectrum bacteriocin enterocin AS-48 was tested for biopreservation of ready-to-eat vegetable foods (soups and purees) against aerobic mesophilic endospore-forming bacteria. By adding AS-48 (10 microg/ml), Bacillus cereus LWL1 was completely inhibited in all six vegetable products tested (natural vegetable cream, asparagus cream, traditional soup, homemade-style traditional soup, vegetable soup, and vichyssoise) for up to 30 days at 6, 15, and 22 degrees C. A collection of strains isolated from spoiled purees showed slightly higher resistance to AS-48 in the order Paenibacillus sp. > Bacillus macroides > B. cereus, although they were also completely inhibited in natural vegetable cream by AS-48 at 10 microg/ml. However, cocktails of five or eight strains composed of B. cereus (three strains), B. macroides (two strains), and Paenibacillus sp., Paenibacillus polymyxa, and Paenibacillus amylolyticus showed higher bacteriocin resistance with AS-48 of up to 50 microg/ml required for complete inactivation in natural vegetable cream stored at 22 degrees C. Repetitive extragenic palindromic sequence-based PCR (REP-PCR) analysis showed that paenibacilli (along with some B. cereus) was the predominant survivor in the cocktails after bacteriocin treatment. To increase the effectiveness of enterocin AS-48, the bacteriocin was tested (at 20 microg/ml) against the eight-strain cocktail in natural vegetable cream in combination with other antimicrobials. The combination of AS-48 and nisin had a slight but significant additive effect. Bactericidal activity was greatly enhanced by phenolic compounds (carvacrol, eugenol, geraniol, and hydrocinnamic acid), achieving a rapid and complete inactivation of bacilli in the tested puree at 22 degrees C.

  8. Survival of escherichia coli o157:h7 co-cultured with different levels of pseudomonas fluorescens and lactobacillus plantarum on fresh beef

    Directory of Open Access Journals (Sweden)

    P. A. Tshabalala

    2012-12-01

    Full Text Available The purpose of this study was to investigate the effect of different levels of Pseudomonas fluorescens (10² and 10(6log10 cfu/mland Lactobacillus plantarum (10² and 10(4log10 cfu/mlon the growth of Escherichia coli O157:H7 on beef loins. Beef loins inoculated with E. coli O157:H7 and P. fluorescens were aerobically stored for 7 days at 4 ºC, while those inoculated with E. coli O157:H7 and L. plantarum were vacuum packaged and stored for 8 weeks at 4 ºC. Aerobic Plate Counts (APC, E. coli O157:H7 and either P. fluorescens or L. plantarum counts were determined at different storage intervals. For the aerobically packaged beef loins, E. coli O157:H7 was detected throughout the 7 day storage period regardless of the P. fluorescens level in the inoculum. For the vacuum packaged beef loins, similar inoculum levels of E. coli O157:H7 and L. plantarum allowed E. coli O157:H7 to survive until week 5 of storage, while a higher inoculum level of L. plantarum inhibited E. coli O157:H7 from week 3. Once fresh beef has been contaminated with E. coli O157:H7, the level of P. fluorescens in the background flora does not inhibit its survival and growth. However, under vacuum storage, the application of L. plantarum as a biopreservative inhibits the survival of E. coli O157:H7 on beef. The higher the level of L. plantarum in the system, the earlier the onset of the inhibition. Farmers and abattoirs have to strengthen preventive strategies to eliminate contamination of beef carcasses with E. coli O157:H7.

  9. Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

    Science.gov (United States)

    Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

    2017-02-01

    The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml(-1) or 8 log c.f.u g(-1)) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

  10. Role of porins in sensitivity of Escherichia coli to antibacterial activity of the lactoperoxidase enzyme system.

    Science.gov (United States)

    De Spiegeleer, Philipp; Sermon, Jan; Vanoirbeek, Kristof; Aertsen, Abram; Michiels, Chris W

    2005-07-01

    Lactoperoxidase is an enzyme that contributes to the antimicrobial defense in secretory fluids and that has attracted interest as a potential biopreservative for foods and other perishable products. Its antimicrobial activity is based on the formation of hypothiocyanate (OSCN-) from thiocyanate (SCN-), using H2O2 as an oxidant. To gain insight into the antibacterial mode of action of the lactoperoxidase enzyme system, we generated random transposon insertion mutations in Escherichia coli MG1655 and screened the resultant mutants for an altered tolerance of bacteriostatic concentrations of this enzyme system. Out of the ca. 5,000 mutants screened, 4 showed significantly increased tolerance, and 2 of these had an insertion, one in the waaQ gene and one in the waaO gene, whose products are involved in the synthesis of the core oligosaccharide moiety of lipopolysaccharides. Besides producing truncated lipopolysaccharides and displaying hypersensitivity to novobiocin and sodium dodecyl sulfate (SDS), these mutants were also shown by urea-SDS-polyacrylamide gel electrophoresis analysis to have reduced amounts of porins in their outer membranes. Moreover, they showed a reduced degradation of p-nitrophenyl phosphate and an increased resistance to ampicillin, two indications of a decrease in outer membrane permeability for small hydrophilic solutes. Additionally, ompC and ompF knockout mutants displayed levels of tolerance to the lactoperoxidase system similar to those displayed by the waa mutants. These results suggest that mutations which reduce the porin-mediated outer membrane permeability for small hydrophilic molecules lead to increased tolerance to the lactoperoxidase enzyme system because of a reduced uptake of OSCN-.

  11. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    Science.gov (United States)

    Kumar, Sasidharan Nishanth; Sreekala, Sreerag Ravikumar; Chandrasekaran, Dileep; Nambisan, Bala; Anto, Ruby John

    2014-01-01

    The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs) [cyclo-(L-Pro-Gly), cyclo(L-Tyr-L-Tyr), cyclo-(L-Phe-Gly) and cyclo(4-hydroxy-L-Pro-L-Trp)]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp). To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp) to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp). The cyclo(4-hydroxy-L-Pro-L-Trp) was nontoxic to two normal cell lines [fore skin (FS) normal fibroblast and African green monkey kidney (VERO)] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp) identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp) could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  12. Synergized antimicrobial activity of eugenol incorporated polyhydroxybutyrate films against food spoilage microorganisms in conjunction with pediocin.

    Science.gov (United States)

    Narayanan, Aarthi; Neera; Mallesha; Ramana, Karna Venkata

    2013-07-01

    Biopolymers and biopreservatives produced by microorganisms play an essential role in food technology. Polyhydroxyalkanoates and bacteriocins produced by bacteria are promising components to safeguard the environment and for food preservation applications. Polyhydroxybutyrate (PHB)-based antimicrobial films were prepared incorporating eugenol, from 10 to 200 μg/g of PHB. The films were evaluated for antimicrobial activity against foodborne pathogens, spoilage bacteria, and fungi such as Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Aspergillus flavus, Aspergillus niger, Penicillium sp., and Rhizopus sp. The synergistic antimicrobial activity of the films in the presence of crude pediocin was also investigated. The broth system containing pediocin (soluble form) as well as antimicrobial PHB film demonstrated an extended lag phase and a significant growth reduction at the end of 24 h against the bacteria. Crude pediocin alone could not elicit antifungal activity, while inhibition of growth and sporulation were observed in the presence of antimicrobial PHB film containing eugenol (80 μg/g) until 7 days in the case of molds, i.e., A. niger, A. flavus, Penicillium sp., and Rhizopus sp. in potato dextrose broth. In the present study, we identified that use of pediocin containing broth in conjunction with eugenol incorporated PHB film could function in synergized form, providing effective hurdle toward food contaminating microorganisms. Furthermore, tensile strength, percent crystallinity, melting point, percent elongation to break, glass transition temperature, and seal strength of the PHB film with and without eugenol incorporation were investigated. The migration of eugenol on exposure to different liquid food simulants was also analyzed using Fourier transform infrared spectroscopy. The study is expected to provide applications for pediocin in conjunction with eugenol containing PHB film to enhance the shelf life of foods in the

  13. Evaluation of the control ability of five essential oils against Aspergillus section Nigri growth and ochratoxin A accumulation in peanut meal extract agar conditioned at different water activities levels.

    Science.gov (United States)

    Passone, María A; Girardi, Natalia S; Etcheverry, Miriam

    2012-10-15

    as effective non-toxic biopreservatives against OTA contamination in stored peanuts.

  14. Antibacterial activity of papain and bromelain on Alicyclobacillus spp.

    Science.gov (United States)

    dos Anjos, Márcia Maria; da Silva, Angela Aparecida; de Pascoli, Isabela Carolini; Mikcha, Jane Martha Graton; Machinski, Miguel; Peralta, Rosane Marina; de Abreu Filho, Benício Alves

    2016-01-04

    Alicyclobacillus spp. are spore forming bacteria that are often related to the deterioration of acidic products such as beverages and citrus juices. After the process of industrial pasteurization, the spore produced by the bacteria can germinate and the microorganism can grow, causing sensory abnormalities in the product. Alternative biopreservatives, such as the antimicrobial compounds, are of considerable importance to the food industry. Papain and bromelain are proteolytic enzymes derived frompapaya and pineapple, respectively. These enzymes are widely used in medicine and in the pharmaceutical and food industries, but while some studies have described their antibacterial action, no studies of the Alicyclobacillus spp. exist. The aimof this studywas to analyze the antibacterial effect of papain and bromelain on Alicyclobacillus spp. through 1) determining minimum inhibitory and bactericidal concentration (MIC and MBC); 2) determining the death time curve of the micro-organism in the presence and absence of enzymes; and 3) investigating the enzymatic mechanism on the microorganism. The antibacterial activity of enzymes in combination with nisin was also evaluated. The results showed that for the Alicyclobacillus acidoterrestris strain, the MIC of papain was 0.98 μg/mL and the MBC was 3.91 μg/mL, while theMIC of bromelain was 62.5 μg/mL and the MBCwas 250 μg/mL. The concentration of 4 ×MIC for both the enzymes was sufficient to eliminate 4 logs of the micro-organism after 24 h of incubation. Through the use of enzyme inhibitors specific for cysteine proteases, it was found that the antibacterial activity of papain and bromelain is not related to its proteolytic activity, butmay be related to other activities, such as amidse and esterase. The synergistic activity of the enzymes revealed a fractional inhibitory concentration (FIC) level of 0.16. Combination with nisin revealed an FIC of 0.25 for papain and 0.19 for bromelain, indicating synergism between both

  15. A spin-drying technique for lyopreservation of mammalian cells.

    Science.gov (United States)

    Chakraborty, Nilay; Chang, Anthony; Elmoazzen, Heidi; Menze, Michael A; Hand, Steven C; Toner, Mehmet

    2011-05-01

    . Membrane integrity after spin drying is therefore considerably higher than what is achieved by conventional drying methods; where about 90% of cells lose membrane integrity at 0.4 gH₂O/gdw (Acker et al. Cell Preserv. Technol. 1(2):129-140, 2002; Elliott et al. Biopreserv. Biobank. 6(4):253-260, 2009).

  16. 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.

  17. 乳酸菌细菌素和超高压联合处理对低温切片火腿的防腐保鲜效果%Combinatorial Preservative Effect of Bacteriocin and High Hydrostatic Pressure on Refrigerated Sliced Vacuum-packaged Cooked Ham

    Institute of Scientific and Technical Information of China (English)

    刘国荣; 孙勇; 王成涛; 郑海涛; 李平兰; 王洋

    2012-01-01

    In order to evaluate technological feasibility of combinatorial treatment using bacteriocin and high hydrostatic pressure as the preservative in refrigerated sliced vacuum-packaged cooked ham,the combinatorial effect of high hydrostatic pressure(600 MPa for 5 min) and enterocin LM-2(320 AU/g) on microorganism amount,and physicochemical and sensory properties of sliced cooked ham was analyzed during the storage at 4 ℃.Results indicated that the combinatorial treatment could substantially suppress the growth of microflora,inhibit the accumulation of TVB-N and decelerate lipid oxidation,and keep a better sensory profile during the storage period of refrigerated sliced cooked ham.The combinatorial treatment revealed the most effective preservation,which could extend the shelf life of sliced cooked ham up to 100 days.These results suggested the combinatorial application of enterocin LM-2 and high hydrostatic pressure has a great potential as a bio-preservative during the storage of refrigerated sliced cooked ham.%为了揭示乳酸菌细菌素和超高压联合处理对低温切片火腿的防腐保鲜效果,并探讨乳酸菌细菌素和超高压联合处理在低温肉制品防腐保鲜应用中的可行性,在不添加任何化学防腐剂的情况下,分别以乳酸菌细菌素(enterocin LM-2)添加量320AU/g、600MPa超高压处理5min以及两者联合处理低温切片火腿,考察联合处理对样品中微生物数量、理化指标以及感官特性的影响。结果表明:enterocin LM-2和超高压技术的联合使用可明显延长低温切片火腿的货架期,有效减少贮藏过程中挥发性盐基氮的生成及脂肪氧化,并保持产品原有色泽、气味、质构等感官特性。综合微生物和理化特性分析结果,联合处理组的防腐效果最好,可将低温切片火腿的货架期延长至100d。

  18. 转基因植物乳杆菌LP590体外耐受性质的研究%Study on tolerance to multistresses in vitro for genetically modified Lactobacillus 590

    Institute of Scientific and Technical Information of China (English)

    刘海燕; 郭星; 许文涛; 王洪新; 田洪涛; 黄昆仑

    2011-01-01

    Lactobacillus as lactic acid bacteria has many excellent traits, which meets the needs of industrial production. Genetically modified (GM) LP590 was obtained from LP by inserting into the gene nisin,which can resist nisin and play a role in bio-preservative. To overall assess the safety of GM LP590 and establish an evaluation model in vitro, some useful explorations were carried out. The ability of LP590 to environmental tolerance(52℃,4℃, ethanol, oxygen, and osmotic stresses)were assessed. LP590 had similar tolerance to LP in 4℃ and ethanol (20%) within 240min. Notably, LP590 can more tolerate of high temperature (52℃), H2 O2 (2%) and NaCl (4.0mol/L) thar LP. The above results indicated that GM LP590 had many good biological characteristics and good prospects for industrial applications. It was a useful and comprehensive exploration to establish a new evaluation model in vitro for genetically modified micro-organisms.%植物乳杆菌是乳酸菌中的一种,它具有许多适应于工业生产的优良性质.转基因乳杆菌LP590是由植物乳杆菌LP为亲本,插入nisin基因得到的.为了研究转基因植物乳杆菌LP590的体外耐受性质,本实验以LP590作为对照,将LP590对高温(52℃)、低温(4℃)、乙醇(20%)、过氧化氢(2%)、氯化钠(4mol/L)的耐受性进行了研究.研究表明,LP590与LP在4℃和20%乙醇环境中暴露240min,两株菌有相同的耐受性.而LP590比LP更加耐受高温(52℃)、过氧化氢(2%)和氯化钠(4mol/L).从研究结果可以看出,转基因植物乳杆菌LP590的体外耐受性总体优于LP,这也为从整体上评价转基因微生物提供了依据.

  19. 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

    similar to pediocin PA-1 and enterocin B, were isolated from non-fermented shellfish. The adaptation of the cultures to seafood matrices may be advantageous in terms of application as a biopreservation strategy for reduction of L. monocytogenes levels in seafood products.

  20. The antilisterial effect of Leuconostoc carnosum 4010 and leucocins 4010 in the presence of sodium chloride and sodium nitrite examined in a structured gelatin system.

    Science.gov (United States)

    Hornbaek, Tina; Brocklehurst, Tim F; Budde, Birgitte Bjørn

    2004-04-15

    To further enhance biopreservation of meat products, the antilisterial effect of the newly described protective culture Leuconostoc carnosum 4010 and its bacteriocins, leucocins 4010, was examined in the presence of sodium chloride and sodium nitrite in a solid matrix using a structured gelatin system. Interaction between Listeria monocytogenes 4140 and Leuc. carnosum 4010 or the leucocins 4010-resistant mutant L. monocytogenes 4140P showed that the inhibitory effect of Leuc. carnosum 4010 in the gelatin system was caused by the production and activity of leucocins 4010. The presence of sodium chloride (2.5% w/v) and sodium nitrite (60 mg/l) reduced the antilisterial effect of Leuc. carnosum 4010 in the structured gel system compared to the use of Leuc. carnosum 4010 alone. Investigations carried out at 10 degrees C showed that the lag phase of L. monocytogenes 4140 in the presence of Leuc. carnosum 4010 was reduced from 71 to 58 h by the addition of sodium chloride and to 40 h by the addition of sodium nitrite. Addition of sodium chloride increased the maximum specific growth rate of L. monocytogenes 4140 in the presence of Leuc. carnosum 4010 from 0.02 to 0.06 h(-1), whereas no change was observed by the addition of sodium nitrite. Compared to the antilisterial effect of leucocins 4010 alone, the addition of sodium chloride (2.5%, w/v) decreased the antilisterial effect at high concentrations of leucocins 4010 (5.3 and 10.6 AU/ml) as measured after 11 days of incubation at 10 degrees C. In gels with added leucocins 4010, the most pronounced reduction in growth of L. monocytogenes 4140 was observed at the highest concentration of leucocins 4010 (10.6 AU/ml) together with sodium nitrite (60 mg/l). More detailed information on the lag phase and the maximum specific growth rate of single colonies of L. monocytogenes 4140 in the presence of leucocins 4010 was obtained using microscopy and image analysis. No pronounced difference in the growth of single colonies was

  1. Evaluation of the probiotic potential and effect of encapsulation on survival for Lactobacillus plantarum ST16Pa isolated from papaya.

    Science.gov (United States)

    Todorov, Svetoslav D; Leblanc, Jean Guy; Franco, Bernadette D G M

    2012-03-01

    bacteriocinogenic LAB isolated from papaya that presents application in food biopreservation and may be beneficial to the consumer health due to its potential probiotic characteristics.

  2. Isolation and identification of microorganisms and antibacterial activity of Laban Zeer, an Egyptian traditional fermented milk product

    Directory of Open Access Journals (Sweden)

    Farag Ali Saleh

    2013-03-01

    not suitable environment for growth and activity of such pathogen and would eliminate the pathogen early enough before the products were made ready for consumption. The microorganisms isolated from Laban Zeer can be used widely in the food fermentation industry as starter culture and bio-preservatives due to their broad inhibition spectrum.

  3. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    Directory of Open Access Journals (Sweden)

    Sasidharan Nishanth Kumar

    Full Text Available The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs [cyclo-(L-Pro-Gly, cyclo(L-Tyr-L-Tyr, cyclo-(L-Phe-Gly and cyclo(4-hydroxy-L-Pro-L-Trp]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp. To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp. The cyclo(4-hydroxy-L-Pro-L-Trp was nontoxic to two normal cell lines [fore skin (FS normal fibroblast and African green monkey kidney (VERO] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  4. Lytic activity of the virion-associated peptidoglycan hydrolase HydH5 of Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88

    Directory of Open Access Journals (Sweden)

    Donovan David M

    2011-06-01

    Full Text Available Abstract Background Staphylococcus aureus is a food-borne pathogen and the most common cause of infections in hospitalized patients. The increase in the resistance of this pathogen to antibacterials has made necessary the development of new anti-staphylococcal agents. In this context, bacteriophage lytic enzymes such as endolysins and structural peptidoglycan (PG hydrolases have received considerable attention as possible antimicrobials against gram-positive bacteria. Results S. aureus bacteriophage vB_SauS-phiIPLA88 (phiIPLA88 contains a virion-associated muralytic enzyme (HydH5 encoded by orf58, which is located in the morphogenetic module. Comparative bioinformatic analysis revealed that HydH5 significantly resembled other peptidoglycan hydrolases encoded by staphylococcal phages. The protein consists of 634 amino acid residues. Two putative lytic domains were identified: an N-terminal CHAP (cysteine, histidine-dependent amidohydrolase/peptidase domain (135 amino acid residues, and a C-terminal LYZ2 (lysozyme subfamily 2 domain (147 amino acid residues. These domains were also found when a predicted three-dimensional structure of HydH5 was made which provided the basis for deletion analysis. The complete HydH5 protein and truncated proteins containing only each catalytic domain were overproduced in E. coli and purified from inclusion bodies by subsequent refolding. Truncated and full-length HydH5 proteins were all able to bind and lyse S. aureus Sa9 cells as shown by binding assays, zymogram analyses and CFU reduction analysis. HydH5 demonstrated high antibiotic activity against early exponential cells, at 45°C and in the absence of divalent cations (Ca2+, Mg2+, Mn2+. Thermostability assays showed that HydH5 retained 72% of its activity after 5 min at 100°C. Conclusions The virion-associated PG hydrolase HydH5 has lytic activity against S. aureus, which makes it attractive as antimicrobial for food biopreservation and anti

  5. New Insights into the Anti-pathogenic Potential of Lactococcus garvieae against Staphylococcus aureus Based on RNA Sequencing Profiling

    Science.gov (United States)

    Delpech, Pierre; Rifa, Etienne; Ball, Graham; Nidelet, Sabine; Dubois, Emeric; Gagne, Geneviève; Montel, Marie-Christine; Delbès, Céline; Bornes, Stéphanie

    2017-01-01

    The bio-preservation potential of Lactococcus garvieae lies in its capacity to inhibit the growth of staphylococci, especially Staphylococcus aureus, in dairy products and in vitro. In vitro, inhibition is modulated by the level of aeration, owing to hydrogen peroxide (H2O2) production by L. garvieae under aeration. The S. aureus response to this inhibition has already been studied. However, the molecular mechanisms of L. garvieae underlying the antagonism against S. aureus have never been explored. This study provides evidence of the presence of another extracellular inhibition effector in vitro. This effector was neither a protein, nor a lipid, nor a polysaccharide, nor related to an L-threonine deficiency. To better understand the H2O2-related inhibition mechanism at the transcriptome level and to identify other mechanisms potentially involved, we used RNA sequencing to determine the transcriptome response of L. garvieae to different aeration levels and to the presence or absence of S. aureus. The L. garvieae transcriptome differed radically between different aeration levels mainly in biological processes related to fundamental functions and nutritional adaptation. The transcriptomic response of L. garvieae to aeration level differed according to the presence or absence of S. aureus. The higher concentration of H2O2 with high aeration was not associated with a higher expression of L. garvieae H2O2-synthesis genes (pox, sodA, and spxA1) but rather with a repression of L. garvieae H2O2-degradation genes (trxB1, ahpC, ahpF, and gpx). We showed that L. garvieae displayed an original, previously undiscovered, H2O2 production regulation mechanism among bacteria. In addition to the key factor H2O2, the involvement of another extracellular effector in the antagonism against S. aureus was shown. Future studies should explore the relation between H2O2-metabolism, H2O2-producing LAB and the pathogen they inhibit. The nature of the other extracellular effector should also

  6. 7种食品防腐剂对肉制品污染微生物的抑菌效果比较研究%Comparison of Antibacterial Effects of Seven Food Preservatives on Spoilage Microorganisms in Meat

    Institute of Scientific and Technical Information of China (English)

    杨晓韬; 李春; 周晓宏

    2012-01-01

    通过测定抑菌率和最低抑菌质量浓度,研究化学防腐剂山梨酸钾、双乙酸钠、单辛酸甘油酯、乙二胺四乙酸二钠(EDTA)以及生物防腐剂乳酸链球菌素(Nisin)、壳聚糖、ε-聚赖氨酸(ε-PL)对12株肉制品腐败(包括2株环状芽孢杆菌(Bacillus circulans)、3株枯草芽孢杆菌(Bacillus subtilis)、3株地衣芽孢杆菌(Bacillus lichenifotrois)、2株凝结芽孢杆菌(Bacillus coagulans)、1株蜂房哈夫尼亚菌(Hafnia alvei)以及1株肠球菌(Enterococcus))的抑菌活性。结果表明:7种防腐剂对供试菌都有一定的抑菌效果,抑菌效果强弱顺序为:Nisin〉壳聚糖〉ε—PL〉单辛酸甘油酯〉EDTA〉双乙酸钠〉山梨酸钾。3种生物防腐剂的抑菌效果明显强于其他4种化学防腐剂。通过比较各种防腐剂对不同种和同种不同株的细菌的抑菌效果,表明同一种防腐剂不仅对不同种的细菌抑菌效果不同,即使对同种不同株的细菌其抑菌效果也有很大差异。%The antibacterial activities of food preservatives including potassium sorbate, sodium diacetate, capryl monoglyceride, disodium ethylene-diamine-tetraacetate (EDTA), nisin, chitosan and ε -polylysine (ε-PL) against 12 meat spoilage strains such as 2 Bacillus circulans strains, 3 Bacillus subtilis strains, 3 Bacillus licheniformis strains, 2 Bacillus coagulans strains, 1 Hafnia alvei strain and an Enterococcus strain were investigated based on inhibitory rate and minimum inhibitory concentration. The results showed that seven food preservatives had inhibitory effect on all tested bacteria at different levels. They could be ranked in decreasing order of antibacterial activity as follows: nisin 〉 chitosan 〉 ε-PL 〉 capryl monoglyceride 〉 EDTA 〉 sodium diacetate 〉potassium sorbate. Three bio-preservatives including nisin, chitosan and ε-PL had better antibacterial activity than other four

  7. Biocontrole de Listeria monocytogenes por Pediococcus acidilactici em couve minimamente processada Biocontrol of Listeria monocytogenes by Pediococcus acidilactici in fresh-cut kale

    Directory of Open Access Journals (Sweden)

    Wanessa Altimiras Costa

    2009-12-01

    selected as a possible biological control bacterium. The population of L. monocytogenes inoculated in minimally processed kale increased 3.7 and 4.7 logarithmic cycles at 5 and 10 °C, respectively, after 20 days of storage and 4.6 logarithmic cycles at 15 °C after eight days. However, when 10(8 CFU.g-1 of P. acidilactici CCA3 was inoculated into processed product a reduction of L. monocytogenes of 2.3 logarithmic cycles under extreme temperature conditions (15 °C occurred. P. acidilactici CCA3 did not alter the titratable acidity or the kale sensorial characteristics during the shelf life period. These results suggest the potential application of biopreservatives on minimally processed kale that need to be associated with refrigeration and sanitation to assure safety.

  8. 水产品生物保鲜技术研究进展%Review of biological preservation technology in aquatic product

    Institute of Scientific and Technical Information of China (English)

    刘尊英; 曾名湧

    2014-01-01

    食品的保鲜与防腐一直是人们普遍关注的问题。传统的化学防腐剂如苯甲酸钠、亚硝酸钠等具有一定的毒性。因此,寻找安全无毒的生物保鲜剂取代化学防腐剂已成为人们关注的热点。生物保鲜剂来源于生物体自身组成成分或其代谢产物,安全无毒、可被生物降解、不会造成二次污染。本文综述了常见生物保鲜剂壳聚糖、有机酸、茶多酚、乳酸链球菌素、生物酶等生物保鲜剂单独或联合使用时对水产品生理生化特性、细菌总数及货架期的影响,比较分析了上述生物保鲜剂在不同水产品应用过程中所呈现的保鲜效果的差异,阐述了生物保鲜剂在水产品保鲜过程中的可能机制,提出了我国水产品生物保鲜剂依然存在提取分离困难、纯化工艺复杂、生物保鲜技术成本高、应用范围窄等问题。针对我国生物保鲜技术存在的主要问题,提出了一些对策。%Food storage and preservation has been the focus of attention of the people. The traditional chemical preservatives such as sodium benzoate and sodium nitrite have certain toxicity. Therefore, researches for safe non-toxic bio-preservative to replace chemical preservative had become the focus of attention. Biological preservative compositions derived from organism itself or its metabolites, which possessescharacteristic of tasteless, non-toxic, safe, biodegradable and no secondary pollution, is causing widespread concern. In this paper, effects of chitosan, organic acids, polyphenols, nisin, and biological enzymes on physiological and biochemical characteristics, the total number of bacteria and shelf of aquatic products were reviewed. A comparative analysis of the difference in the biological preservative fresh-keeping effect of application in different aquatic product process was presented. The main problems including separation and purification of biological preservatives, high cost and

  9. Systematic study on antagonist application to the preservation of juicy peach fruits at room temperature%利用拮抗菌常温保鲜凤凰水蜜桃效果系统研究

    Institute of Scientific and Technical Information of China (English)

    王亦佳; 李建龙; 刚诚成; 高建刚; 俞忠; 钱伟东

    2012-01-01

    As using chemical preservatives on fruits are harmful to humans and environment, antagonist (Cryptococcus laurentii and Bacillus subtilis) used alone or combinated with sodium bicarbonate solution (concentration of 2% )was evaluated for preservation of juicy peach ( Prunus persica)fruits.The fruits were dipped in suspensions of C. laurentii and B. subtilis or in sodium bicarbonate solution, after treatments, packed with wrapping bag and stored at room temperature(25~C).5 days later,8 physiological and biochemical indexes of juicy peach fruits were measured, such as water loss rate, rot rate, fruit firmness, soluble solids, respiratory intensity, relative electric conductivity, MDA and PPO activity.The results showed that C.laurentii or B.subtilis used alone was most effective,in which the B.subtilis was better, whereas the sodium bicarbonate solution used alone was the worst and the combinated treatment was in the middle.Therefore, antagonist preparation was a kind of effective and pollution-free biopreservation preparation for juicy peach,suitable for popularization and application.%由于使用化学保鲜剂对环境和人体存在危害,故观测和比较了两种病原菌拮抗菌——罗伦隐球酵母(Cryptococcus laurentii)和枯草芽孢杆菌(Bacillus subtilis)单独使用和与化学试剂(2%NaHCO3)配合使用对张家港市凤凰水蜜桃(Prunuspersica)采后保鲜品质的影响。,实验采取直接浸果的方式,果实处理后装入保鲜袋置于常温条件下(25℃),放置5d后测量其失重率、腐烂程度、硬度、可溶性固形物含量、呼吸强度、相对电导率、丙二醛(MDA)含量和多酚氧化酶(PPO)含量8种生理指标。结果表明:单独使用拮抗菌液的处理组果实保鲜效果最佳,其中枯草芽孢杆菌效果尤为显著;单独使用化学试剂处理组保鲜效果最差,二者结合处理组的效果居中。因此.对凤凰水蜜桃而

  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. 抗猪链球菌戊糖乳杆菌素的纯化及特性研究%Purification and characterization of pentocin against streptococcus suis

    Institute of Scientific and Technical Information of China (English)

    武朋朋; 刘国荣; 畅晓渊; 张香美; 李平兰

    2011-01-01

    addition, the bacteriocin had a broad inhibitory spectrum. It not only had a strong antimicrobial effect on gram-positive,such as streptococcus suis, Listeria monocytogenes, Staphylococcus aereu and etc, but also could inhibited several gram-negative bacteria, such as Escherichia coil, Pseudomonas spp and etc. These results indicated that the bacteriocin has a potential application as food additives and bio-preservatives in food industry.

  12. Actividad antimicrobiana de Weissella confusa y sus metabolitos frente a Escherichia coli y Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Liliana Serna Cock

    2013-12-01

     and their metabolites against E. coli, and K. pneumoniae, (two pathogens causing foodborne illness was evaluated, in order to know the possible use in food processing. W. confusa was produced by batch fermentation using MRS commercial substrate. Three fermentations, of 6 hours at 33 ° C, without aeration, stirring continuously (100 rpm were performed. In every hour of fermentation, three biological substances, W. confusa with their metabolites (W + W10b, W. confusa free cells metabolites (W, and metabolite (W10b were separated, and subsequently the antimicrobial activity against pathogenic E. coli and K. pneumoniae was measured. Statistically significant differences between treatments and fermentation time were found. Treatment (W against E. coli, showed the greatest antimicrobial activity, it was obtained between the fourth and the sixth hours of fermentation (2.45 cm inhibition diameter average. In treatments W and W + W10b against K. pneumoniae, statistically significant differences between them were not found. The antimicrobial activity was shown between the fourth and fifth hour of fermentation. W. confusa and W10b have antimicrobial activity against E. coli andK. pneumoniae, suggesting that W and W10b could be used as an alternative to biopreservation or bioprotection of fresh and processed food for human and animal consumption, and could become an alternative to antibiotics used for diseases caused by E. coli and K. pneumoniae.Key words: bioconservation, food, diseases, biotechnology applications.

  13. Antibacterial activity of nisin, oregano essential oil, EDTA, and their combination against Salmonella Enteritidis for application in mayonnaise | Avaliação de atividade antibacteriana de nisina, óleo essencial de orégano, EDTA e sua combinação contra Salmonella Enteritidis para aplicação na maionese

    Directory of Open Access Journals (Sweden)

    Janine Passos Lima da Silva

    2016-04-01

    Full Text Available Salmonella Enteritidis (SE is one of the most important serovars associated with Salmonella gastroenteritis outbreaks in Brazil. The use of natural antimicrobials can be an alternative method of SE control. The antimicrobial effect of two oregano essential oils (OEO1 and OEO2 at 0.1%, 0.2%, 0.5%, 1.0%, or 2.0%; nisin (Nisaplin® at 0, 6.25, 12.5, or 25 ppm; ethylenediaminetetraacetic acid (EDTA at 0.0037%, 0.0056%, 0.0075%, 0.0110%, or 0.0150%; and their combination against SE in vitro was studied to be applied in mayonnaise and Russian salad made with the same mayonnaise during storage at 8º or 30ºC for 24 hours. OEO was very efficient against SE at all tested concentrations, while nisin and EDTA showed no effect against SE. Ten volatile components were identified in the two OEOs using gas chromatography coupled to mass spectrometry with electron impact ionization, with carvacrol being the major component of both samples. OEO2, containing p-cymene (15.95% and y-terpinene (6.90%, besides carvacrol (61.66%, resulted in larger inhibition zone than the other OEO (OEO1 don’t contains p-cymene or y-terpinene. Nisin in combination with OEO1 or OEO2 had an antagonistic effect at all concentrations. The presence of nisin caused a reduction in essential oil antimicrobial activity (p≤0.05. Sensory evaluation showed that consumers prefer 0.2% OEO in mayonnaise instead of 0.5% and 1.0% concentrations. Thus, OEO only, at a concentration of 0.2%, was applied in mayonnaise against SE. The Russian salad prepared with mayonnaise plus OEO at 0.2% (wt/wt caused a reduction of SE when compared with the salad prepared with mayonnaise without OEO. These results indicate that the use of OEO as a biopreservative (natural antimicrobial can enhance food safety, serving as an additional barrier in helping the Good Manufacturing Practices and the Hazard Analysis Critical Control Point program, fundamental to food safety

  14. 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