Journal articles on the topic 'Bacteriocins'
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1
Joshi, Khyati, Pravir Kumar, and Rashmi Kataria. "Bacteriocins as promising alternatives to conventional antimicrobial agents." Research Journal of Biotechnology 18, no. 4 (March 15, 2023): 133–40. http://dx.doi.org/10.25303/1804rjbt1330140.
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Bacteriocins are bacterially synthesized ribosomal antimicrobial peptides which hinder the growth of closely related or unrelated bacterial species. They are often compared to antibiotics due to their significant bactericidal properties. Reports suggest that almost all bacteria synthesize bacteriocins as a part of their innate immunity. Bacteriocin production is dependent on a number of process variables such as aeration, pH, temperature and the type of carbon and nitrogen source used. Bacteriocin applications are primarily focused on food preservation. However, resistance to conventional antimicrobial agents offers novel prospects for bacteriocin applications. Several recent studies have purified bacteriocins for food preservation, infection control, cancer therapy, peptic ulcers etc. This study summarises the classification of bacteriocins, their mechanism of action, factors affecting bacteriocin production and the applications of bacteriocins as antimicrobial agents.
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OUMER, A., S. GARDE, P. GAYA, M. MEDINA, and M. NUÑEZ. "The Effects of Cultivating Lactic Starter Cultures with Bacteriocin-Producing Lactic Acid Bacteria." Journal of Food Protection 64, no. 1 (January 1, 2001): 81–86. http://dx.doi.org/10.4315/0362-028x-64.1.81.
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The effects of bacteriocins produced by six strains of lactic acid bacteria on 9 mesophilic and 11 thermophilic commercial starter cultures were investigated in mixed cultures of commercial starters with bacteriocin-producing strains in milk. The bacteriocins produced by the test organisms were nisin A, nisin Z, lacticin 481, enterocin AS-48, a novel enterocin, and a novel plantaricin. Mesophilic commercial starters were in most cases tolerant of bacteriocins, with only two of the starters being partially inhibited, one by four and the other by two bacteriocins. The aminopeptidase activities of mesophilic starters were generally low, and only one of the combinations of mesophilic starter–bacteriocin producer gave double the aminopeptidase activity of the starter culture without the bacteriocin producer. Thermophilic commercial starters were more sensitive to bacteriocins than mesophilic starters, with six thermophilic starters being partially inhibited by at least one of the bacteriocins. Their aminopeptidase activities were generally higher than those of the mesophilic starters. The aminopeptidase activities of seven thermophilic starters were increased in the presence of bacteriocins, by factors of up to 9.0 as compared with the corresponding starter cultures alone. Bacteriocin-producing strains may be used as adjunct cultures to mesophilic starters for the inhibition of pathogens in soft and semihard cheeses, because mesophilic starters are rather tolerant of bacteriocins. Bacteriocin producers may also be used as adjunct cultures to thermophilic starters of high aminopeptidase activity, more sensitive to lysis by bacteriocins than mesophilic starters, for the acceleration of ripening in semihard and hard cheeses.
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Cintas, L. M., M. P. Casaus, C. Herranz, I. F. Nes, and P. E. Hernández. "Review: Bacteriocins of Lactic Acid Bacteria." Food Science and Technology International 7, no. 4 (August 2001): 281–305. http://dx.doi.org/10.1106/r8de-p6hu-clxp-5ryt.
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During the last few years, a large number of new bacteriocins produced by lactic acid bacteria (LAB) have been identified and characterized. LAB-bacteriocins comprise a heterogeneous group of physicochemically diverse ribosomally-synthesized peptides or proteins showing a narrow or broad antimicrobial activity spectrum against Gram-positive bacteria. Bacteriocins are classified into separate groups such as the lantibiotics (Class I); the small (<10 kDa) heat-stable postranslationally unmodified non-lantibiotics (Class II), further subdivided in the pediocin-like and anti Listeria bacteriocins (subclass IIa), the two-peptide bacteriocins (subclass IIb), and the sec-dependent bacteriocins (subclass IIc); and the large (>30 kDa) heat-labile non-lantibiotics (Class III). Most bacteriocins characterized to date belong to Class II and are synthesized as precursor peptides (preprobacteriocins) containing an N-terminal double-glycine leader peptide, which is cleaved off concomitantly with externalization of biologically active bacteriocins by a dedicated ABC-transporter and its accessory protein. However, the recently identified sec-dependent bacteriocins contain an N-terminal signal peptide that directs bacteriocin secretion through the general secretory pathway (GSP). Most LAB-bacteriocins act on sensitive cells by destabilization and permeabilization of the cytoplasmic membrane through the formation of transitory poration complexes or ionic channels that cause the reduction or dissipation of the proton motive force (PMF). Bacteriocin producing LAB strains protect themselves against the toxicity of their own bacteriocins by the expression of a specific immunity protein which is generally encoded in the bacteriocin operon. Bacteriocin production in LAB is frequently regulated by a three-component signal transduction system consisting of an induction factor (IF), and histidine protein kinase (HPK) and a response regulator (RR). This paper presents an updated review on the general knowledge about physicochemical properties, molecular mode of action, biosynthesis, regulation and genetics of LAB-bacteriocins.
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Drider, Djamel, Gunnar Fimland, Yann Héchard, Lynn M. McMullen, and Hervé Prévost. "The Continuing Story of Class IIa Bacteriocins." Microbiology and Molecular Biology Reviews 70, no. 2 (June 2006): 564–82. http://dx.doi.org/10.1128/mmbr.00016-05.
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SUMMARY Many bacteria produce antimicrobial peptides, which are also referred to as peptide bacteriocins. The class IIa bacteriocins, often designated pediocin-like bacteriocins, constitute the most dominant group of antimicrobial peptides produced by lactic acid bacteria. The bacteriocins that belong to this class are structurally related and kill target cells by membrane permeabilization. Despite their structural similarity, class IIa bacteriocins display different target cell specificities. In the search for new antibiotic substances, the class IIa bacteriocins have been identified as promising new candidates and have thus received much attention. They kill some pathogenic bacteria (e.g., Listeria) with high efficiency, and they constitute a good model system for structure-function analyses of antimicrobial peptides in general. This review focuses on class IIa bacteriocins, especially on their structure, function, mode of action, biosynthesis, bacteriocin immunity, and current food applications. The genetics and biosynthesis of class IIa bacteriocins are well understood. The bacteriocins are ribosomally synthesized with an N-terminal leader sequence, which is cleaved off upon secretion. After externalization, the class IIa bacteriocins attach to potential target cells and, through electrostatic and hydrophobic interactions, subsequently permeabilize the cell membrane of sensitive cells. Recent observations suggest that a chiral interaction and possibly the presence of a mannose permease protein on the target cell surface are required for a bacteria to be sensitive to class IIa bacteriocins. There is also substantial evidence that the C-terminal half penetrates into the target cell membrane, and it plays an important role in determining the target cell specificity of these bacteriocins. Immunity proteins protect the bacteriocin producer from the bacteriocin it secretes. The three-dimensional structures of two class IIa immunity proteins have been determined, and it has been shown that the C-terminal halves of these cytosolic four-helix bundle proteins specify which class IIa bacteriocin they protect against.
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Vogel, Verena, and Barbara Spellerberg. "Bacteriocin Production by Beta-Hemolytic Streptococci." Pathogens 10, no. 7 (July 9, 2021): 867. http://dx.doi.org/10.3390/pathogens10070867.
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Beta-hemolytic streptococci cause a variety of infectious diseases associated with high morbidity and mortality. A key factor for successful infection is host colonization, which can be difficult in a multispecies environment. Secreting bacteriocins can be beneficial during this process. Bacteriocins are small, ribosomally produced, antimicrobial peptides produced by bacteria to inhibit the growth of other, typically closely related, bacteria. In this systematic review, bacteriocin production and regulation of beta-hemolytic streptococci was surveyed. While Streptococcus pyogenes produces eight different bacteriocins (Streptococcin A-FF22/A-M49, Streptin, Salivaricin A, SpbMN, Blp1, Blp2, Streptococcin A-M57), only one bacteriocin of Streptococcus agalactiae (Agalacticin = Nisin P) and one of Streptococcus dysgalactiae subsp. equisimilis (Dysgalacticin) has been described. Expression of class I bacteriocins is regulated by a two-component system, typically with autoinduction by the bacteriocin itself. In contrast, a separate quorum sensing system regulates expression of class II bacteriocins. Both identified class III bacteriocins are plasmid-encoded and regulation has not been elucidated.
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Zhang, Tingting, Yu Zhang, Lin Li, Xiuqi Jiang, Zhuo Chen, Fan Zhao, and Yanglei Yi. "Biosynthesis and Production of Class II Bacteriocins of Food-Associated Lactic Acid Bacteria." Fermentation 8, no. 5 (May 10, 2022): 217. http://dx.doi.org/10.3390/fermentation8050217.
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Bacteriocins are ribosomally synthesized peptides made by bacteria that inhibit the growth of similar or closely related bacterial strains. Class II bacteriocins are a class of bacteriocins that are heat-resistant and do not undergo extensive posttranslational modification. In lactic acid bacteria (LAB), class II bacteriocins are widely distributed, and some of them have been successfully applied as food preservatives or antibiotic alternatives. Class II bacteriocins can be further divided into four subcategories. In the same subcategory, variations were observed in terms of amino acid identity, peptide length, pI, etc. The production of class II bacteriocin is controlled by a dedicated gene cluster located in the plasmid or chromosome. Besides the pre-bacteriocin encoding gene, the gene cluster generally includes various combinations of immunity, transportation, and regulatory genes. Among class II bacteriocin-producing LAB, some strains/species showed low yield. A multitude of fermentation factors including medium composition, temperature, and pH have a strong influence on bacteriocin production which is usually strain-specific. Consequently, scientists are motivated to develop high-yielding strains through the genetic engineering approach. Thus, this review aims to present and discuss the distribution, sequence characteristics, as well as biosynthesis of class II bacteriocins of LAB. Moreover, the integration of modern biotechnology and genetics with conventional fermentation technology to improve bacteriocin production will also be discussed in this review.
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Todorov, Svetoslav Dimitrov, Igor Popov, Richard Weeks, and Michael Leonidas Chikindas. "Use of Bacteriocins and Bacteriocinogenic Beneficial Organisms in Food Products: Benefits, Challenges, Concerns." Foods 11, no. 19 (October 10, 2022): 3145. http://dx.doi.org/10.3390/foods11193145.
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This review’s objective was to critically revisit various research approaches for studies on the application of beneficial organisms and bacteriocins as effective biopreservatives in the food industry. There are a substantial number of research papers reporting newly isolated bacterial strains from fermented food products and their application as potential probiotics, including partial characterization of bacteriocins produced by these microorganisms. Most of these studies follow scientific community-accepted standard procedures and propose various applications of the studied strains and bacteriocins as potential biopreservatives for the food industry. A few investigations go somewhat further, performing model studies, exploring the application of expressed bacteriocins in a designed food product, or trying to evaluate the effectiveness of the studied potential probiotics and bacteriocins against foodborne pathogens. Some authors propose applications of bacteriocin producers as starter cultures and are exploring in situ bacteriocin production to aid in the effective control of foodborne pathogens. However, few studies have evaluated the possible adverse effects of bacteriocins, such as toxicity. This comes from well-documented reports on bacteriocins being mostly non-immunogenic and having low cytotoxicity because most of these proteinaceous molecules are small peptides. However, some studies have reported on bacteriocins with noticeable cytotoxicity, which may become even more pronounced in genetically engineered or modified bacteriocins. Moreover, their cytotoxicity can be very specific and is dependent on the concentration of the bacteriocin and the nature of the targeted cell. This will be discussed in detail in the present review.
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Hassan, Mahreen Ul, Hina Nayab, Tayyab Ur Rehman, Mike P. Williamson, Khayam Ul Haq, Nuzhat Shafi, and Farheen Shafique. "Characterisation of Bacteriocins Produced by Lactobacillus spp. Isolated from the Traditional Pakistani Yoghurt and Their Antimicrobial Activity against Common Foodborne Pathogens." BioMed Research International 2020 (September 12, 2020): 1–10. http://dx.doi.org/10.1155/2020/8281623.
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Lactic acid bacteria (LAB) are widely known for their probiotic activities for centuries. These bacteria synthesise some secretory proteinaceous toxins, bacteriocins, which help destroy similar or interrelated bacterial strains. This study was aimed at characterising bacteriocins extracted from Lactobacillus spp. found in yoghurt and assessing their bactericidal effect on foodborne bacteria. Twelve isolated Lactobacillus spp. were examined to produce bacteriocins by the organic solvent extraction method. Bacteriocins produced by two of these strains, Lactobacillus helveticus (BLh) and Lactobacillus plantarum (BLp), showed the most significant antimicrobial activity, especially against Staphylococcus aureus and Acinetobacter baumannii. Analysis of SDS-PAGE showed that L. plantarum and L. helveticus bacteriocins have a molecular weight of ~10 kDa and ~15 kDa, respectively. L. plantarum (BLp) bacteriocin was heat stable while L. helveticus (BLh) bacteriocin was heat labile. Both bacteriocins have shown activity at acidic pH. Exposure to a UV light enhances the activity of the BLh; however, it had negligible effects on the BLp. Different proteolytic enzymes confirmed the proteinaceous nature of both the bacteriocins. From this study, it was concluded that bacteriocin extracts from L. helveticus (BLh) can be considered a preferable candidate against foodborne pathogens as compared to L. plantarum (BLp). These partially purified bacteriocins should be further processed to attain purified product that could be useful for food spoilage and preservation purposes.
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Teber, Rabeb, and Shuichi Asakawa. "In Silico Screening of Bacteriocin Gene Clusters within a Set of Marine Bacillota Genomes." International Journal of Molecular Sciences 25, no. 5 (February 22, 2024): 2566. http://dx.doi.org/10.3390/ijms25052566.
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Due to their potential application as an alternative to antibiotics, bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by bacteria, have received much attention in recent years. To identify bacteriocins within marine bacteria, most of the studies employed a culture-based method, which is more time-consuming than the in silico approach. For that, the aim of this study was to identify potential bacteriocin gene clusters and their potential producers in 51 marine Bacillota (formerly Firmicutes) genomes, using BAGEL4, a bacteriocin genome mining tool. As a result, we found out that a majority of selected Bacillota (60.78%) are potential bacteriocin producers, and we identified 77 bacteriocin gene clusters, most of which belong to class I bacteriocins known as RiPPs (ribosomally synthesized and post-translationally modified peptides). The identified putative bacteriocin gene clusters are an attractive target for further in vitro research, such as the production of bacteriocins using a heterologous expression system.
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Zimina, Maria, Olga Babich, Alexander Prosekov, Stanislav Sukhikh, Svetlana Ivanova, Margarita Shevchenko, and Svetlana Noskova. "Overview of Global Trends in Classification, Methods of Preparation and Application of Bacteriocins." Antibiotics 9, no. 9 (August 28, 2020): 553. http://dx.doi.org/10.3390/antibiotics9090553.
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This paper summarizes information about the division of bacteriocins into classes (Gram-negative bacteria, Gram-positive bacteria, and archaea). Methods for producing bacteriocins have been studied. It is known that bacteriocins, most successfully used today are products of secondary metabolism of lactic acid bacteria. It is established that the main method of bacteriocin research is PCR analysis, which makes it possible to quickly and easily identify the presence of bacteriocin encoding genes. The mechanism of cytotoxic action of bacteriocins has been studied. It is proved that the study of cytotoxic (antitumor) activity in laboratory conditions will lead to the clinical use of bacteriocins for cancer treatment in the near future. It is established that the incorporation of bacteriocins into nanoparticles and targeted delivery to areas of infection may soon become an effective treatment method. The delivery of bacteriocins in a concentrated form, such as encapsulated in nanoparticles, will increase their effectiveness and minimize potential toxic side effects. The analysis of publications on this topic confirmed that diverse research on bacteriocins is relevant.
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Al-Haddad, Ahmed Mohammed, Wedad Mohammed Al-Haik, Yasser Mansour Matran, and Ibrahim Mohammed Bawazir. "Antimicrobial activity of Lactobacillus acidophilus bacteriocin against clinical isolates." IP International Journal of Medical Microbiology and Tropical Diseases 9, no. 3 (September 15, 2023): 182–88. http://dx.doi.org/10.18231/j.ijmmtd.2023.035.
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Lactic acid bacteria serve as important human probiotics, as they can produce bacteriocins from different dairy sources, and the antimicrobial activity of their bacteriocins have been documented in the scientific field. This study aimed to assess the antimicrobial activities of bacteriocin obtained from different dairy sources. An experimental analytical design was used to isolate species on de Man, Rogosa and Sharpe Media, and identify them phenotypically and evaluated their bacteriocin's antimicrobial activity against four clinical isolates. SPSS Version 22 was used for Statistical purposes. A total of 14 isolates were verified from various sample sources. These included 6 isolates from camel's milk, 2 from goat's milk, 3 from local yogurt, and 3 from Omani yogurt. The supernatants of most isolates exhibited varying levels of antimicrobial activity during the investigation. Furthermore, the action of the bacteriocin was concentration dependent. The highest level of inhibition was 14 mm for Staphylococcus aureus, 12 mm for, 12 mm for and 10 mm for when using 100μl of raw bacteriocin. Moreover, the correlation between bacteriocin activity, temperatures, and incubation times was found to be irreversible. The study reveals inherent antibacterial traits in species from local milk and milk products in Al-Shihr Town. Specifically, variant, synthesizing bacteriocin, effectively suppressed the clinical isolates, showcasing their pathogen-fighting ability. These findings offer potential for developing efficient antimicrobial methods, utilizing bacteriocin as an antibiotic in food and medicine.
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Masuda, Y., T. Zendo, and K. Sonomoto. "New type non-lantibiotic bacteriocins: circular and leaderless bacteriocins." Beneficial Microbes 3, no. 1 (March 1, 2012): 3–12. http://dx.doi.org/10.3920/bm2011.0047.
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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.
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Wang, Yu, Nan Shang, Yueying Huang, Boya Gao, and Pinglan Li. "The Progress of the Biotechnological Production of Class IIa Bacteriocins in Various Cell Factories and Its Future Challenges." International Journal of Molecular Sciences 25, no. 11 (May 26, 2024): 5791. http://dx.doi.org/10.3390/ijms25115791.
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Class IIa bacteriocins produced in lactic acid bacteria are short cationic peptides with antimicrobial activity. In the search for new biopreservation agents, class IIa bacteriocins are considered to be the best potential candidates, not only due to their large abundance but also because of their high biological activity and excellent thermal stability. However, regulated by the biosynthetic regulatory system, the natural class IIa bacteriocin yield is low, and the extraction process is complicated. The biotechnological production of class IIa bacteriocins in various cell factories has been attempted to improve this situation. In this review, we focus on the application of biotechnological routes for class IIa bacteriocin production. The drawbacks and improvements in the production of class IIa bacteriocins in various cell factories are discussed. Furthermore, we present the main challenge of class IIa bacteriocins, focusing on increasing their production by constructing suitable cell factories. Recombinant bacteriocins have made considerable progress from inclusion body formation, dissolved form and low antibacterial activity to yield recovery. The development of prospective cell factories for the biotechnological production of bacteriocins is still required, which may facilitate the application of bacteriocins in the food industry.
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Manoharan, Manovina, and Thamarai Selvi Balasubramaniam. "An Extensive Review on Production, Purification, and Bioactive Application of Different Classes of Bacteriocin." Journal of Tropical Biodiversity and Biotechnology 7, no. 3 (September 9, 2022): 72735. http://dx.doi.org/10.22146/jtbb.72735.
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Lactic Acid Bacteria (LAB) synthesize various metabolites during their growth phase and are Generally Recognized as Safe (GRAS) and Qualified Presumption of Safety (QPS). Ribosomally synthesized Antimicrobial Peptides (AMP) or Bacteriocins from the genera of Lactic Acid Bacteria and other prokaryotic genera are cationic, heat-stable, amphiphilic and the membrane permeabilizing peptides built with an excess amount of lysyl and arginyl residues. Antimicrobial compounds produced by LAB depend on the physical and biological conditions of microbial culture. Different classes of bacteriocin are produced by both Gram-positive and Gram-negative bacteria. The production of bacteriocin is influenced by various environmental factors. Bacteriocin has a wide variety of applications in various fields. The application spectrum of bacteriocins can be expanded in various domains such as food processing, biomedical, and personal care due to the increase in the number of newly discovered bacteriocins. Bacteriocins acquire a wide spectrum of antimicrobial activity with minimal level of cytotoxicity. In addition, bacteriocins were studied for their anticancer activity against different cancer cell lines. Selective binding of bacteriocins (cationic) towards cancer cells (anionic) increases the cytotoxicity of cancer cells. Bacteriocin peptides initiate necrosis by communicating with the cell surface which selectively targets and kills the cells with tumor formation and does not cause any damage to the normal healthy cells. In this review, the bacteriocins synthesized from lactic acid bacteria along with their interaction with cancer cell lines and other applications are discussed along with a few examples of other bioactive compounds produced by LAB.
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Pérez-Ramos, Adrián, Désiré Madi-Moussa, Françoise Coucheney, and Djamel Drider. "Current Knowledge of the Mode of Action and Immunity Mechanisms of LAB-Bacteriocins." Microorganisms 9, no. 10 (October 7, 2021): 2107. http://dx.doi.org/10.3390/microorganisms9102107.
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Bacteriocins produced by lactic acid bacteria (LAB-bacteriocins) may serve as alternatives for aging antibiotics. LAB-bacteriocins can be used alone, or in some cases as potentiating agents to treat bacterial infections. This approach could meet the different calls and politics, which aim to reduce the use of traditional antibiotics and develop novel therapeutic options. Considering the clinical applications of LAB-bacteriocins as a reasonable and desirable therapeutic approach, it is therefore important to assess the advances achieved in understanding their modes of action, and the resistance mechanisms developed by the producing bacteria to their own bacteriocins. Most LAB-bacteriocins act by disturbing the cytoplasmic membrane through forming pores, or by cell wall degradation. Nevertheless, some of these peptides still have unknown modes of action, especially those that are active against Gram-negative bacteria. Regarding immunity, most bacteriocin-producing strains have an immunity mechanism involving an immunity protein and a dedicated ABC transporter system. However, these immunity mechanisms vary from one bacteriocin to another.
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Inglis, R. Fredrik, Alex R. Hall, and Angus Buckling. "The role of ‘soaking’ in spiteful toxin production in Pseudomonas aeruginosa." Biology Letters 9, no. 1 (February 23, 2013): 20120569. http://dx.doi.org/10.1098/rsbl.2012.0569.
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The ubiquitous production of antibacterial toxins, such as bacteriocins, is an ecologically significant class of interbacterial interactions that have primarily evolved through their indirect fitness benefits to the producer. Bacteria release bacteriocins into the environment at a cost to individual cell, but individual bacteriocin-producing cells are unlikely to gain any direct benefit from their own toxin; indeed, cell lysis is required in many species. There is a growing body of research describing the ecological conditions that can favour the evolution of bacteriocin production. However, an important aspect of many bacteriocins has yet to be investigated: the ability of bacteriocin-producing cells to neutralize toxin (‘soaking’) produced by other clonemates. By competing Pseudomonas aeruginosa bacteriocin-producing wild-type and ‘non-soaking’ strains against a bacteriocin-susceptible strain, we find that soaking markedly reduces the fitness of a bacteriocin-producing strain at both high and low frequencies.
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METAXOPOULOS (Ι. ΜΕΤΑΞΟΠΟΥΛΟΣ), J., M. MATARAGAS (M. ΜΑΤΑΡΑΓΚΑΣ), and E. H. DROSINOS (Ε.Χ. ΔΡΟΣΙΝΟΣ). "Bacteriocins of lactic acid bacteria and their application on food as biopreservatives. (II)." Journal of the Hellenic Veterinary Medical Society 54, no. 1 (December 19, 2017): 69. http://dx.doi.org/10.12681/jhvms.15221.
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Lactic acid bacteria produce a variety of small molecular weight compounds, which have antimicrobial properties. Such substances are: organic acids, alcohols, carbon dioxide, diacetyl, hydrogen peroxide and bacteriocins. Many of these compounds have a wide inhibitory spectrum but the bacteriocins are able to inhibit species, namely, related with the bacteriocin-producing strain. In the last years bacteriocins have gained a lot of concern because some of them are able to inhibit the growth of pathogenic bacteria, like Listeria monocytogenes. The term "biopreservation" refers to the extension of storage life, as well as to the enhancement of the food safety, using the bacteriocin-producing lactic acid strains or their metabolic antibacterial products. In this review will be reported bacteriocins, which are produced by the lactic acid bacteria and will be discussed the potential application of the bacteriocinogenic strains or their bacteriocins on the foods, as protective cultures or as protective compounds, respectively.
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Ovchinnikov, Kirill V., Hai Chi, Ibrahim Mehmeti, Helge Holo, Ingolf F. Nes, and Dzung B. Diep. "Novel Group of Leaderless Multipeptide Bacteriocins from Gram-Positive Bacteria." Applied and Environmental Microbiology 82, no. 17 (June 17, 2016): 5216–24. http://dx.doi.org/10.1128/aem.01094-16.
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ABSTRACTFrom raw milk we found 10Lactococcus garvieaeisolates that produce a new broad-spectrum bacteriocin. Though the isolates were obtained from different farms, they turned out to possess identical inhibitory spectra, fermentation profiles of sugars, and repetitive sequence-based PCR (rep-PCR) DNA patterns, indicating that they produce the same bacteriocin. One of the isolates (L. garvieaeKS1546) was chosen for further assessment. Purification and peptide sequencing combined with genome sequencing revealed that the antimicrobial activity was due to a bacteriocin unit composed of three similar peptides of 32 to 34 amino acids. The three peptides are produced without leader sequences, and their genes are located next to each other in an operon-like structure, adjacent to the genes normally involved in bacteriocin transport (ABC transporter) and self-immunity. The bacteriocin, termed garvicin KS (GarKS), showed sequence homology to four multipeptide bacteriocins in databases: the known staphylococcal aureocin A70, consisting of four peptides, and three unannotated putative multipeptide bacteriocins produced byBacillus cereus. All these multipeptide bacteriocin loci show conserved genetic organization, including being located adjacent to conserved genetic determinants (Cro/cI and integrase) which are normally associated with mobile genetic elements or genome rearrangements. The antimicrobial activity of all multipeptide bacteriocins was confirmed with synthetic peptides, and all were shown to have broad antimicrobial spectra, with GarKS being the most active of them. The inhibitory spectrum of GarKS includes important pathogens belonging to the generaStaphylococcus,Bacillus,Listeria, andEnterococcus.IMPORTANCEBacterial resistance to antibiotics is a very serious global problem. There are no new antibiotics with novel antimicrobial mechanisms in clinical trials. Bacteriocins use antimicrobial mechanisms different from those of antibiotics and can kill antibiotic-resistant bacteria, but the number of bacteriocins with very broad antimicrobial spectra is very small. In this study, we have found and purified a novel three-peptide bacteriocin, garvicin KS. By homology search, we were able to find one known and three novel sequence-related bacteriocins consisting of 3 or 4 peptides. None of the peptides has modified amino acids in its sequence. Thus, the activity of all bacteriocins was confirmed with chemically synthesized peptides. All of them, especially garvicin KS, have very broad antibacterial spectra, thus representing a great potential in antimicrobial applications in the food industry and medicine.
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OLADIPO, IYABO C., ABIODUN I. SANNI, WRITACHIT CHAKRABORTY, SOMNATH CHAKRAVORTY, SAYANTAN JANA, DEEP S. RUDRA, RATAN GACCHUI, and SNEHASIKTA SWARNAKAR. "Bioprotective Potential of Bacteriocinogenic Enterococcus gallinarum Strains Isolated from Some Nigerian Fermented Foods, and of their Bacteriocins." Polish Journal of Microbiology 63, no. 4 (2014): 415–22. http://dx.doi.org/10.33073/pjm-2014-056.
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Enterococcus gallinarum strains isolated from some Nigerian fermented foods were found to produce bacteriocins. The bacteriocins had a broad spectrum of activity against both Gram-positive and negative bacteria. The effects of the bacteriocins and bacteriocinogenic organ- isms on Staphylococcus aureus infections in rats were evaluated. Sprague-Dawley rats were infected with S. aureus MTCC 737 and treated with E. gallinarum T71 and different concentrations of the bacteriocins from E. gallinarum W211 and T71. Staphylococcus aureus infection caused significant upregulation of aspartate aminotransferase and alanine aminotransferase levels in sera of the infected rats. Moreover, gelatin zymography revealed that infected gastric tissues showed elevated matrix metalloproteinase-9 activity. Bacteriocin treatments reduced the MMP-9 activity and inhibited the expressions of both Tumour Necrosis Factor Alpha (TNF-α) and Interleukin-1 Beta (IL-1β) dose dependently, pointing to a potential role of the bacteriocins in attenuating inflammatory responses to Staphylococcus aureus infec- tion. Gastric and GIT damage caused by staphylococcal infection were reduced in the Enterococcus gallinarum T71 and bacteriocin-treated groups also dose dependently. We conclude that these bacteriocins may have useful biomedical applications.
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Feliatra, Feli, Zainal Abidin Muchlisin, Hiwan Yuda Teruna, Widya Rahmi Utamy, Nursyirwani Nursyirwani, and Andi Dahliaty. "Potential of bacteriocins produced by probiotic bacteria isolated from tiger shrimp and prawns as antibacterial to Vibrio, Pseudomonas, and Aeromonas species on fish." F1000Research 7 (March 29, 2018): 415. http://dx.doi.org/10.12688/f1000research.13958.1.
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Backgrounds: Bacteriocin has been used widely in industry as a biopreservative agent. The objective of the present study was to investigate the potency of Bacteriocin isolated from tiger prawnPenaeus monodonand freshwater shrimpMacrobrachium rosenbergiias an anti-bacterial on fish.Methods: A total of ten candidates of probiotic bacteria consisted of five isolates from tiger shrimps (H1, H2, H3, H4, H5) and five isolates from freshwater prawns (W1, W2, W3, W4, W5) were evaluated. Bacteriocin wasBacteriocin was produced by centrifugation at a speed of 150 rpm and at 37 °C for 24 hours. The bacteriocin extract was purified by adding sulphate ammonium salt {(NH4) 2SO4} at 80% of the saturation level. Bacteriocin activity was determined using a diffusion method against pathogenic bacteriaVibrio alginolyticus,Aeromonas hydrophillaAeromonas hydrophillaandPseudomonas stutzeri. Bacteriocins were analyzed usinganalyzedusing High Performance Liquid Chromatography (HPLC) and Fourier Transform Infra-Red (FTIR). The data were subjected to analysis of variance (ANOVA) and followed with Duncans multiple range test.Results: Bacteriocins produced by bacteria isolate H4 from tiger prawn indicated the highest bacteriocin activity againstbacteriocin activity againstPseudomonas stutzeriatstutzeriat the diameter of inhibition zone of 887.10 ± 409.24 mm2/mL. While isolate W2 from freshwater shrimp indicated inhibition zone of 1466.96 ± 127.62 mm2/mL. Both bacteriocins were purified by chromatography column using Sephadex LH-20.Conclusions: This finding showed that bacterial isolates H4 and W2 have the potential to produce bacteriocins which inhibit the pathogenic bacteria. FTIR analysis showed an amide group at wave number 1652cm-1contained in the bacteriocins of isolates H4 and W2.
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Islam, Md Nahidul, Nahinur Rahman Akhand, Arafat Al Mamun, Asaduzzaman Shishir, Marufa Zerin Aktar, Shakila Nargis Khan, Md Mozammel Hoq, and Mohammad Shahnoor Hossain. "Screening and Characterization of Bacteriocin-Like Inhibitory Substances Produced by Bangladeshi Strains of Bacillus thuringiensis." Bangladesh Pharmaceutical Journal 18, no. 2 (July 26, 2015): 149–56. http://dx.doi.org/10.3329/bpj.v18i2.24314.
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Bacteriocins are ribosomally synthesized antibacterial peptides which have the potential to be used as natural food preservatives as well as alternative to antibiotics. Here, we report the production of bacteriocin-like inhibitory substances (BLIS) from the indigenous strains of Bacillus thuringiensis. Deferred antagonism bacteriocin assay and agar well diffusion methods suggested that several of the tested strains have high levels of bacteriocin-like activity against the common food-borne pathogens, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus. These bacteriocins are generally produced at the mid-logarithmic phase of growth with optimum temperature of 37 ºC, pH-7.0 and 24 h of incubation. Heat stability assay demonstrated that the bacteriocins produced from the strains are highly heat stable and can retain activity up to 100 ºC. Our study suggests that these bacteriocins may be potential candidates for use as biodegradable natural food preservatives and alternative antimicrobial agents to solve the increasing trends of problems of antibiotic resistance.Bangladesh Pharmaceutical Journal 18(2): 149-156, 2015
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Bonini, Marcel, Antonio Carlos Maringoni, and Julio Rodrigues Neto. "Characterization of Xanthomonas spp. strains by bacteriocins." Summa Phytopathologica 33, no. 1 (March 2007): 24–29. http://dx.doi.org/10.1590/s0100-54052007000100003.
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Twenty-five strains of Xanthomonas axonopodis pv. citri and 14 strains of Xanthomonas spp. were tested for bacteriocin production. X. axonopodis pv. passiflorae strains were sensitive to the bacteriocins produced by the 25 X. axonopodis pv. citri strains evaluated in this study while strains of X. axonopodis pv. manihotis and X. campestris pv. campestris showed variable sensitivity. Only five of the 25 X. axonopodis pv. citri strains were not inhibited by the bacteriocins produced by the two X. axonopodis pv. passiflorae strains. The bacteriocins produced by the Xanthomonas axonopodis pv. citri (FDC-806) and X. axonopodis pv. passiflorae (Mar-2850 A) strains were thermolabile, resistant to lysozyme and sensitive to DNAse. The bacteriocin produced by X. axonopodis pv. passiflorae was resistant to the action of proteinase K, trypsin and RNAse while the bacteriocin produced by X. axonopodis pv. citri was sensitive to these enzymes. The bacteriocins produced by X. axonopodis pv. passiflorae and X. axonopodis pv. citri were called passifloricin and citricin, respectively.
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MURINDA, S. E., K. A. RASHID, and R. F. ROBERTS. "In Vitro Assessment of the Cytotoxicity of Nisin, Pediocin, and Selected Colicins on Simian Virus 40–Transfected Human Colon and Vero Monkey Kidney Cells with Trypan Blue Staining Viability Assays." Journal of Food Protection 66, no. 5 (May 1, 2003): 847–53. http://dx.doi.org/10.4315/0362-028x-66.5.847.
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Gram-positive bacterial bacteriocins (nisin and pediocin) and gram-negative bacterial bacteriocins (colicins [Col] E1, E3, E6, E7, and K) were evaluated for cytotoxicity against cultured simian virus 40–transfected human colon (SV40-HC) and Vero monkey kidney (Vero) cells. Bacteriocin-treated cells were assessed for viability by trypan blue staining. Monolayers of SV40-HC and Vero cells were cultured in tissue culture plates (35°C, 10% CO2 in humidified air) with the use of Dulbecco's modified Eagle's medium supplemented with 10% (vol/vol) calf serum. Actively growing cells in the log phase (ca. 104 cells per ml) were treated with individual partially purified bacteriocin preparations at 170, 350, and 700 activity units per ml. Duplicate culture plates for each bacteriocin treatment and untreated controls were withdrawn after 16, 32, and 48 h of incubation. Cells were dissociated with trypsin and treated with trypan blue and were then counted in a hemocytometer with the use of a phase-contrast microscope. Viability assays indicated dose-dependent toxicity for some bacteriocins. Nisin, pediocin, and Col E6 were the most cytotoxic bacteriocins; SV40-HC cells demonstrated greater sensitivity than Vero cells did. Some bacteriocins can be toxic to mammalian cells; therefore, bacteriocins intended for use as biopreservatives must be evaluated for toxicity to mammalian cells and for other toxicities. Col E1, Col E3, Col E7, and Col K demonstrated little toxicity at the activities tested, indicating that they are safe and thus have potential for use as food biopreservatives.
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Vaughan, Anne, Vincent G. H. Eijsink, and Douwe van Sinderen. "Functional Characterization of a Composite Bacteriocin Locus from Malt Isolate Lactobacillus sakei 5." Applied and Environmental Microbiology 69, no. 12 (December 2003): 7194–203. http://dx.doi.org/10.1128/aem.69.12.7194-7203.2003.
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ABSTRACT Lactobacillus sakei 5, isolated from malted barley, produces three bacteriocins. Genetic and functional analysis of the purified bacteriocins showed that this strain produces a plasmid-encoded bacteriocin that is identical to sakacin P, as well as two novel, chromosomally encoded bacteriocins, which were designated sakacin T and sakacin X. The structural genes specifying sakacin T and sakacin X are part of the sakacin TX locus, which consists of two adjacent but divergently oriented gene clusters. The first gene cluster includes stxP, stxR, stxK, and stxT, which, based on functional and comparative sequence analysis, are believed to encode an inducing peptide and proteins involved in regulation and secretion of these bacteriocins. The second gene cluster includes the structural and immunity genes for sakacin T, a class IIb two-peptide bacteriocin composed of SakTα and SakTβ, and sakacin X, a class IIa bacteriocin. Interestingly, a so-called transport accessory protein was absent from the locus, and based on our results it appears that a dedicated accessory protein is not required for processing and transport of sakacin T and sakacin X.
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Penfold, Christopher N., Daniel Walker, and Colin Kleanthous. "How Bugs Kill Bugs: Progress and Challenges in Bacteriocin Research." Biochemical Society Transactions 40, no. 6 (November 21, 2012): 1433–37. http://dx.doi.org/10.1042/bst20120253.
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A Biochemical Society Focused Meeting on bacteriocins was held at the University of Nottingham on 16–18 July 2012 to mark the retirement of Professor Richard James and honour a scientific career of more than 30 years devoted to an understanding of the biology of colicins, bacteriocins produced by Escherichia coli. This meeting was the third leg of a triumvirate of symposia that included meetings at the Île de Bendor, France, in 1991 and the University of East Anglia, Norwich, U.K., in 1998, focused on bringing together leading experts in basic and applied bacteriocin research. The symposium which attracted 70 attendees consisted of 18 invited speakers and 22 selected oral communications spread over four themes: (i) Role of bacteriocins in bacterial ecology, (ii) Mode of action of bacteriocins, (ii) Mechanisms of bacteriocin import across the cell envelope, and (iv) Biotechnological and biomedical applications of bacteriocins. Speakers and poster presenters travelled from around the world, including the U.S.A., Japan, Asia and Europe, to showcase the latest developments in their scientific research.
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Venter, Alexandra P., Sunny Twelker, Ivan J. Oresnik, and Michael F. Hynes. "Analysis of the genetic region encoding a novel rhizobiocin fromRhizobium leguminosarumbv.viciaestrain 306." Canadian Journal of Microbiology 47, no. 6 (June 1, 2001): 495–502. http://dx.doi.org/10.1139/w01-043.
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Cross-testing of a number of strains of Rhizobium leguminosarum for bacteriocin production revealed that strain 306 produced at least two distinct bacteriocins. Further analysis involving plasmid transfer to Agrobacterium and other hosts demonstrated that there were bacteriocin determinants on plasmids pRle306b and pRle306c, as well as a third bacteriocin. The bacteriocin encoded by pRle306b was indistinguishable from the bacteriocin encoded by strain 248, whereas the bacteriocin encoded by plasmid pRle306c had a distinctive spectrum of activity against susceptible strains, as well as different physical properties from other bacteriocins that we have studied in our lab. Two mutants altered in production of the pRle306c bacteriocin were generated by transposon Tn5 mutagenesis, and the DNA flanking the transposon inserts in these mutants was cloned and characterized. DNA sequence analysis suggested that the pRle306c bacteriocin was a large protein belonging to the RTX family, and that a type I secretion system involving an ABC type transporter was required for export of the bacteriocin. A mutant unable to produce this bacteriocin was unaltered in its competitive properties, both in broth and in nodulation assays, suggesting that the bacteriocin may not play a major role in determining the ecological success of this strain.Key words: Rhizobium, bacteriocins, RTX proteins, plasmids.
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Bara, Jeffrey J., Zachary Matson, and Susanna K. Remold. "Life in the cystic fibrosis upper respiratory tract influences competitive ability of the opportunistic pathogen Pseudomonas aeruginosa." Royal Society Open Science 5, no. 9 (September 2018): 180623. http://dx.doi.org/10.1098/rsos.180623.
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Understanding characteristic differences between host-associated and free-living opportunistic pathogens can provide insight into the fundamental requirements for success after dispersal to the host environment, and more generally into the ecological and evolutionary processes by which populations respond to simultaneous selection on complex interacting traits. We examined how cystic fibrosis (CF)-associated and environmental isolates of the opportunistic pathogen Pseudomonas aeruginosa differ in the production of an ecologically important class of proteinaceous toxins known as bacteriocins, and how overall competitive ability depends on the production of and resistance to these bacteriocins. We determined bacteriocin gene content in a diverse collection of environmental and CF isolates and measured bacteriocin-mediated inhibition, resistance and the outcome of competition in a shared environment between all possible pairs of these isolates at 25°C and 37°C. Although CF isolates encoded significantly more bacteriocin genes, our phenotypic assays suggest that they have diminished bacteriocin-mediated killing and resistance capabilities relative to environmental isolates, regardless of incubation temperature. Notably, however, although bacteriocin killing and resistance profiles significantly predicted head-to-head competitive outcomes, CF and environmental isolates did not differ significantly in their competitive ability. This suggests that the contribution of bacteriocins to competitive ability involves selection on other traits that may be pleiotropically linked to interference competition mediated by bacteriocins.
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Gordon, David M., and Claire L. O'Brien. "Bacteriocin diversity and the frequency of multiple bacteriocin production in Escherichia coli." Microbiology 152, no. 11 (November 1, 2006): 3239–44. http://dx.doi.org/10.1099/mic.0.28690-0.
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A collection of 266 faecal isolates of Escherichia coli from humans was assayed for the production of mitomycin C-inducible bacteriocins and screened using a PCR-based method for the presence of eleven colicins and seven microcins. Eight different colicins were detected and all seven microcins. Of the strains examined, 38 % produced a bacteriocin, 24 % produced a colicin and 20 % produced a microcin. Of the 102 bacteriocin-producing strains, 42 % produced one type of bacteriocin, 41 % produced two, 16 % produced three and one strain was found to produce four different bacteriocins. Strains producing more than one bacteriocin were more likely to be members of E. coli genetic group B2 and less likely to belong to genetic groups A or D. Several of the bacteriocins were found to co-occur in a strain more often than would be expected by chance: microcins H47 and M; colicin Ia and microcin V; colicins B and M; colicins E1 and M; colicins E1 and Ia. No bacteriocins released as a consequence of cell lysis were found to co-associate more often than expected by chance. Three non-mutually exclusive hypotheses are presented that might explain the high frequency of multiple bacteriocin production in E. coli strains: (1) expanded killing range, (2) expanded receptor repertoire and (3) fitness benefits in different environments.
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Sârbu, Ionela, Tatiana Vassu, Ileana Stoica, Carmen Chifiriuc, Marcela Bucur, Elena Rusu, Robertina Ionescu, and Diana Pelinescu. "Analysis on the antimicrobial activity of some lactic acid bacteria strains." Romanian Journal of Infectious Diseases 18, no. 2-3 (September 30, 2015): 87–91. http://dx.doi.org/10.37897/rjid.2015.2-3.6.
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Objective. The main objective of this study was to select lactic acid bacteria strains with antimicrobial activity and to identify and characterize the antimicrobial compounds. Methods. In this study we tested the antimicrobial activity of 153 lactic bacteria strains by disk diffusion method against 6 microbial pathogenic strains isolated from patients with urinary and vaginal infections. Results. Antimicrobial test results revealed that most of lactic acid bacteria strains exhibited high antimicrobial activity against pathogenic microorganisms. For most of lactic bacteria strains antimicrobial activity has been correlated with the production of organic acids and only for two strains with the biosynthesis of bacteriocins. Bacteriocin produced by Lactococcus (Lc.) lactis F2a strain presented a broad spectrum of activity and high activity (51,200 AU/ml) compared with bacteriocins isolated from Lactobacillus (Lb.) paracasei ssp. paracasei JR strain (400 AU/ml). The stability tests of bacteriocin revealed that the bacteriocin produced by Lc. lactis F2a strain, it is stable at acid pH while exposure for long time to 600C causes a drastic decrease in bacteriocin activity. Conclusions. Lactic bacteria strains showed a high antimicrobial activity against both prokaryotic and eukaryotic pathogen strains. Two bacterial strains have bacteriocins. Bacteriocins isolated from Lc. lactis F2a strain showed a high activity and a broad spectrum of action.
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Negash, Abebe Worku, and Berhanu Andualem Tsehai. "Current Applications of Bacteriocin." International Journal of Microbiology 2020 (November 3, 2020): 1–7. http://dx.doi.org/10.1155/2020/4374891.
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Bacteriocins are multifunctional, ribosomally produced, proteinaceous substances with pronounced antimicrobial activity at certain concentrations. They are produced by bacteria and certain members of archaea to inhibit the growth of similar or closely related bacterial strains. These molecules have antimicrobial activity against pathogenic and deteriorating bacteria, which justifies their biotechnological potential. They are classified into 3 major classes based on their structural and physicochemical properties: class I bacteriocin, class II bacteriocin, and class III bacteriocin. Bacteriocins inhibit the growth of target organisms by functioning primarily on the cell envelope and by affecting gene expression and protein production within cells. The use of bacteriocins has been reported for the following: food preservation, diverse therapeutic purposes such as treatment of peptic ulcer, spermicidal agent, and woman care, anticancerous agent, veterinary use, skincare, and oral care, and also for plant growth promotion in agriculture among others.
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Krishna, Lal. "THE IDENTIFICATION, PRODUCTION AND CHARACTERIZATION OF NATTOKINASE, BACTERIOCIN FROM BACTERIAL SPECIES." Bacterial Empire 2, no. 4 (October 10, 2019): 91. http://dx.doi.org/10.36547/be.2019.2.4.91-95.
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The study was aimed at identification, production and characterization of nattokinase, bacteriocin from bacterial species. Nattokinase and bacteriocins finds a wide range of applications in Pharmaceutical industry, health care and medicine. Nattokinase is a highly active fibrinolytic enzyme secreted by Bacillus subtilis and bacteriocins are proteinaceous toxins produced by Lactobacillus to inhibit the growth of closely related bacterial strains. Bacillus subtilis and Lactobacillus isolates shown positive results to microscopic, biochemical analysis. The nattokinase and bacteriocins were produced by optimizing the media. The enzymes were purified by ammonium sulfate precipitation and HPLC. The enzyme activity for nattokinase was found at 7 mg/ml, pH 8.0 and temperature 48 ºC and the enzyme activity for bacteriocin was found at 3.9 mg/ml, pH 6.5 and temperature 30 °C. Bacteriocins from Lactobacillus showed good antagonistic activity against pathogenic bacteria. Nattokinase from Bacillus subtilis played a significant role in thrombolytic and anti-coagulation at in vitro. The results indicated that the pure enzyme has a potential in dissolving blood clot.
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Ishibashi, Naoki, Kohei Himeno, Yoshimitsu Masuda, Rodney Honrada Perez, Shun Iwatani, Takeshi Zendo, Pongtep Wilaipun, Vichien Leelawatcharamas, Jiro Nakayama, and Kenji Sonomoto. "Gene Cluster Responsible for Secretion of and Immunity to Multiple Bacteriocins, the NKR-5-3 Enterocins." Applied and Environmental Microbiology 80, no. 21 (August 22, 2014): 6647–55. http://dx.doi.org/10.1128/aem.02312-14.
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ABSTRACTEnterococcus faeciumNKR-5-3, isolated from Thai fermented fish, is characterized by the unique ability to produce five bacteriocins, namely, enterocins NKR-5-3A, -B, -C, -D, and -Z (Ent53A, Ent53B, Ent53C, Ent53D, and Ent53Z). Genetic analysis with a genome library revealed that the bacteriocin structural genes (enkA[ent53A],enkC[ent53C],enkD[ent53D], andenkZ[ent53Z]) that encode these peptides (except for Ent53B) are located in close proximity to each other. This NKR-5-3ACDZ (Ent53ACDZ) enterocin gene cluster (approximately 13 kb long) includes certain bacteriocin biosynthetic genes such as an ABC transporter gene (enkT), two immunity genes (enkIazandenkIc), a response regulator (enkR), and a histidine protein kinase (enkK). Heterologous-expression studies ofenkTand ΔenkTmutant strains showed thatenkTis responsible for the secretion of Ent53A, Ent53C, Ent53D, and Ent53Z, suggesting that EnkT is a wide-range ABC transporter that contributes to the effective production of these bacteriocins. In addition, EnkIaz and EnkIc were found to confer self-immunity to the respective bacteriocins. Furthermore, bacteriocin induction assays performed with the ΔenkRKmutant strain showed that EnkR and EnkK are regulatory proteins responsible for bacteriocin production and that, together with Ent53D, they constitute a three-component regulatory system. Thus, the Ent53ACDZ gene cluster is essential for the biosynthesis and regulation of NKR-5-3 enterocins, and this is, to our knowledge, the first report that demonstrates the secretion of multiple bacteriocins by an ABC transporter.
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Kalmokoff, M. L., S. K. Banerjee, T. Cyr, M. A. Hefford, and T. Gleeson. "Identification of a New Plasmid-Encodedsec-Dependent Bacteriocin Produced by Listeria innocua 743." Applied and Environmental Microbiology 67, no. 9 (September 1, 2001): 4041–47. http://dx.doi.org/10.1128/aem.67.9.4041-4047.2001.
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ABSTRACT Listeria innocua 743 produces an inhibitory activity demonstrating broad-spectrum inhibition of Listeria monocytogenes isolates. Gel-electrophoretic analysis of culture supernatants indicated that two inhibitors with different molecular weights were produced by this strain. Insertion of Tn917into a 2.9 Kb plasmid (pHC743) generated mutants with either an impaired ability or a loss in ability to produce one of the inhibitors. Sequence analysis of the transposon insertion regions revealed the presence of two continuous open reading frames, the first encoding a new pediocin-like bacteriocin (lisA) and the second encoding a protein homologous with genes involved in immunity toward other bacteriocins (lisB). Translation of the bacteriocin gene (lisA) initiates from a noncanonical start codon and encodes a 71-amino-acid prebacteriocin which lacked the double glycine leader peptidase processing site common in other type II bacteriocins. Alignment of the sequence with the processed N termini of related bacteriocins suggests that the mature bacteriocin consists of 43 amino acids, with a predicted molecular mass of 4,484 Da. Mutants containing insertions into lisA were sensitive to the inhibitor, indicating that lisAB forms a single operon and that lisB represents the immunity protein. Cloning of an amplicon containing the lisAB operon intoEscherichia coli resulted in expression and export of the bacteriocin. This finding confirms that the phenotype is dependent on the structural and immunity gene only and that export of this bacteriocin is sec dependent. This is the first confirmation of bacteriocin production in a Listeriaspp., and it is of interest that this bacteriocin is closely related to the pediocin family of bacteriocins produced by lactic acid bacteria.
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Shafique, Bakhtawar, Muhammad Modassar Ali Nawaz Ranjha, Mian Anjum Murtaza, Noman Walayat, Asad Nawaz, Waseem Khalid, Shahid Mahmood, et al. "Recent Trends and Applications of Nanoencapsulated Bacteriocins against Microbes in Food Quality and Safety." Microorganisms 11, no. 1 (December 28, 2022): 85. http://dx.doi.org/10.3390/microorganisms11010085.
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Bacteriocins are ribosomal-synthesized peptides or proteins produced by bacterial strains and can inhibit pathogenic bacteria. Numerous factors influence the potential activity of bacteriocins in food matrices. For example, food additives usage, chemical composition, physical conditions of food, and sensitivity of proteolytic enzymes can constrain the application of bacteriocins as beneficial food preservatives. However, novel bacteriocin nanoencapsulation has appeared as an encouraging solution. In this review, we highlight the bacteriocins produced by Gram-negative bacteria and Gram-positive bacteria including lactic acid bacteria that have shown positive results as potential food preservatives. In addition, this review encompasses the major focus on bacteriocins encapsulation with nanotechnology to enhance the antimicrobial action of bacteriocins. Several strategies can be employed to encapsulate bacteriocins; however, the nanotechnological approach is one of the most effective strategies for avoiding limitations. Nanoparticles such as liposomes, chitosan, protein, and polysaccharides have been discussed to show their importance in the nanoencapsulation method. The nanoparticles are combined with bacteriocins to develop the nano-encapsulated bacteriocins from Gram-negative and Gram-positive bacteria including LAB. In food systems, nanoencapsulation enhances the stability and antimicrobial functionality of active peptides. This nanotechnological application provides a formulation of a broad range of antimicrobial peptides at the industry-scale level. Nano-formulated bacteriocins have been discussed along with examples to show a broader antimicrobial spectrum, increase bacteriocins’ applicability, extend antimicrobial spectrum and enhance stability.
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Haghighatafshar, Hafizeh, Reza Talebi, and Amir Tukmechi. "The Effect of Bacteriocin Isolated From Lactobacillus rhamnosus on Pseudomonas aeruginosa Lipopolysaccharides." Avicenna Journal of Clinical Microbiology and Infection 8, no. 2 (June 29, 2021): 45–50. http://dx.doi.org/10.34172/ajcmi.2021.09.
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Background: Bacteriocins are heterogeneous inhibitory substances that could affect the bacteria belonging to the same genus. Both gram-positive and gram-negative bacteria produce bacteriocins. One of the best sources of producing bacteriocins is Lactobacillus. The aim of this study was to isolate and purify bacteriocin from Lactobacillus rhamnosus and assess its effects on Pseudomonas aeruginosa and synthesis of its lipopolysaccharide. Methods: L. rhamnosus was prepared and cultured at MRS broth and incubated at 37ºC for 24 hours. Then, the medium was centrifuged for the isolation of bacteriocin and the supernatant was considered as bacteriocin. Antibacterial properties of different concentrations of bacteriocin (50, 100, 200, and 400 μg/mL) against P. aeruginosa were assayed by using agar diffusion and broth micro dilution methods. Also, the effect of bacteriocin against lipopolysaccharide synthesis in P. aeruginosa was analyzed by using one unit of minimum inhibitory concentration (MIC) for bacteriocin. Results: The results showed that all bacteriocin concentrations had antibacterial activity against P. aeruginosa. The MIC value was 31.25 μg/mL and minimal bactericidal concentration (MBC) was 62.5 μg/mL. Also, the synthesis of lipopolysaccharide decreased during P. aeruginosa growth period, and it reached zero after 5 hours. Conclusions: The results of this study showed the antibacterial effect of bacteriocin isolated from L. rhamnosus against P. aeruginosa. In addition, this bacteriocin prevented the lipopolysaccharide synthesis in P. aeruginosa.
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Aymerich, M. T., M. Hugas, and J. M. Monfort. "Review : Bacteriocinogenic lactic acid bacteria associated with meat products / Revisión: Bacterias lácticas productoras de bacteriocinas asociadas a productos cárnicos." Food Science and Technology International 4, no. 3 (June 1998): 141–58. http://dx.doi.org/10.1177/108201329800400301.
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Meat consumption is of great economical importance. Several lactic acid bacteria associated with meat products are important natural bacteriocin producers. Bacteriocins are proteinaceous antag onistic substances considered to be important in the control of spoilage and pathogenic microor ganisms. This review aims to present the current state of the art in terms of bacteriocinogenic lactic acid bacteria associated with fresh and fermented meat products, describe the biochemical and genetic characteristics of their bacteriocins and the potential use of bacteriocins production of meat products.
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Ali, Muhamad, Melinda Sanggu Artha, Muhamad Aidil Fadjar Suryadi, Djoko Kisworo, and Muhamad Amin. "The Growth and Bacteriocin Productions of Enterococcus Faecium Cultured in Aerobic and Anaerobic Conditions." IOP Conference Series: Earth and Environmental Science 1036, no. 1 (July 1, 2022): 012063. http://dx.doi.org/10.1088/1755-1315/1036/1/012063.
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Abstract Bacteriocins are antimicrobial compounds produced by diverse members of lactic acid bacteria (LAB). Bacteriocins can be used as food bio preservatives to increase the shelf life of food naturally by preventing or killing foodborne pathogens. One of the lactic acid bacteria that produce bacteriocin is Enterococcus faecium. Some LAB grown on semi-synthetic complex media such as MRS (de Mann Rogosa Sharpe) can make a high population of bacterial cells and relatively large bacteriocins. This study aimed to observe the growth of E. faecium on MRS and LB media under aerobic and anaerobic conditions. Cultures were performed for 4.5h, 5h, 5.5h, 6h, 6.5h, and 7h. The amount of bacteriocin produced was investigated by SDS-PAGE. Meanwhile, the inhibitory activity was measured against Listeria monocytogenes (LM). The results showed that E. faecium grew better in deMan Rogosa Sharp (MRS) medium under anaerobic conditions than in MRS medium under aerobic conditions as well as Luria Bertani (LB) media under aerobic and anaerobic conditions. The SDS-PAGE results showed a protein band measuring about 90 kDa, which was thought to be a bacteriocin. The inhibition test showed a clear zone in the LM culture, which indicated that the bacteria produced bacteriocins that could inhibit the growth of pathogenic bacteria.
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Yuliana, Tri, Annisa Rizka Pratiwi, Shafa Zahratunnisa, Tita Rialita, Yana Cahyana, Putri Widyanti Harlina, and Herlina Marta. "Purification and Partial Characterization of a Bacteriocin Produced by Lactobacillus pentosus 124-2 Isolated from Dadih." Applied Sciences 13, no. 7 (March 28, 2023): 4277. http://dx.doi.org/10.3390/app13074277.
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The fermentation process results in the presence of lactic acid bacteria (LAB). Traditional fermented buffalo milk from the Indonesian province of West Sumatra is known as dadih. Bacteriocins are naturally occurring antimicrobial peptides that can be produced by LAB. These bacteriocins have the potential to be used as natural preservatives. This research was conducted with the intention of isolating and partially characterizing a bacteriocin that was generated by Lactobacillus pentosus 124-2 that was isolated from dadih. Using MRS agar media and 16sRNA, the LAB that was found in dadih was successfully isolated. Bacteriocins were produced using media consisting of MRS broth. After the bacteriocins were obtained, they were subjected to a series of purification processes, one of which included ammonium sulfate (70%) followed by gel filtration chromatography for additional purification. According to the findings, the strain of LAB that was discovered in the dadih was Lactobacillus pentosus 124-2. The specific activity of the bacteriocins rose, allowing for the effective completion of the purification process. The pure bacteriocins had the greatest specific activity values, at 60.59 AU/mg, while the yield values were 0.41% and 3.15-fold. Bacteriocins in their purest form were able to inhibit the growth of Salmonella species as well as Staphylococcus aureus. The characterization results included partial bacteriocins that were resistant to pH 2, 4, and 6; antibacterial activity that was was stable at a temperature range of 25 °C to 121 °C; and resistance to the addition of 2%, 4%, and 6% salt concentrations. Microbial stability against the addition of surfactants EDTA, SDS, and Tween 80 was also obtained. In light of these findings, a bacteriocin derived from L. pentosus possesses the possible ability to be utilized in the food business as a biopreservative.
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Khumbongmayum, Sumita Devi, and Veenagayathri Krishnaswamy. "Potential use of bacteriocin producing lactic acid bacterial strain isolated from milk products and its application as the fish feed." International Journal of Scientific World 4, no. 2 (November 15, 2016): 61. http://dx.doi.org/10.14419/ijsw.v4i2.6802.
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Bacteriocins are gene-encoded inhibitory proteins and those produced by Gram-positive Lactic acid bacteria. Some bacteriocins even display antagonistic activity towards Gram-positive food borne pathogens and spoilage organisms. This present study involves isolation of Bacteriocin-producing lactic acid bacteria from a variety of milk and milk products. The physico-chemical properties of the isolated bacteriocin producing bacterial strains were screened. The isolated bacteriocin bacterial strains were biochemically characterized and identified. Further, the isolated effective bacterial strain was used as a fish feed and its effect on their growth was evaluated. The evaluated data continue to demonstrate that the bacteriocin producing bacterial strains will have greater potential in the food products industry.
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da Costa, Roger J., Flávia L. S. Voloski, Rafael G. Mondadori, Eduarda H. Duval, and Ângela M. Fiorentini. "Preservation of Meat Products with Bacteriocins Produced by Lactic Acid Bacteria Isolated from Meat." Journal of Food Quality 2019 (January 10, 2019): 1–12. http://dx.doi.org/10.1155/2019/4726510.
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Bacteriocins are ribosomal-synthesized antimicrobial peptides that inhibit the growing of pathogenic and/or deteriorating bacteria. The most studied bacteriocin-producing microorganisms are lactic acid bacteria (LAB), as they have great potential application in food biopreservation, since the majority have GRAS (Generally Recognized as Safe) status. The LAB-producing bacteriocins and/or bacteriocins produced by these bacteria have been widely studied, with the emphasis on those derived from milk and dairy products. On the other hand, isolates from meat and meat products are less studied. The objective of this review is to address the main characteristics, classification, and mechanism of action of bacteriocins and their use in food, to highlight studies on the isolation of LAB with bacteriocinogenic potential from meat and meat products and also to characterize, purify, and apply these bacteriocins in meat products. In summary, most of the microorganisms studied areLactococcus,Enterococcus,Pediococcus, andLactobacillus, which produce bacteriocins such as nisin, enterocin, pediocin, pentocin, and sakacin, many with the potential for use in food biopreservation.
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AlSalam A. AlKarem, Kurdistan A., and Suzan .Kamran. Hasan. "The inhibition of selected pathogens by Lactobacillus bulgaricus and Streptococcus thermophiles bacteriocins." Sumer 4 8, CSS 4 (October 15, 2023): 1–10. http://dx.doi.org/10.21931/rb/css/2023.08.04.72.
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Bacteriocins were produced from Lactobacillus bulgaricus, Streptococcus thermophiles and MIX (Lactobacillus bulgaricus, Streptococcus thermophiles) by two methods: Shaker Fermentation and Static Fermentation (aerobic and anaerobic) through bacterial growth in MRS liquid medium, for each of them and the detection of the inhibitory activity on some types of pathogenic bacteria through the growth of the test bacteria on a solid nutrient medium Agar Nutrient. It was found that the three isolates can produce bacteriocin, and there are significant differences between each of the bacteriocins towards the pathogenic bacteria. It shows that the bacteriocin produced from Lactobacillus bulgaricus has a higher inhibitory activity and can inhibit different types of bacteria from gram-positive and gram-negative keywords: Doxazosin, Chloroquine, Synergism, MCF-7, Autophagy. Keywords: Shaker Fermentation. Static Fermentation. Bacteriocins. Lactic acid bacteria.
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Watson, G. N. "The assessment and application of a bacteriocin typing scheme forClostridium perfringens." Journal of Hygiene 94, no. 1 (February 1985): 69–79. http://dx.doi.org/10.1017/s0022172400061143.
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SUMMARYA collection of 50 bacteriocins was assembled and used to type 802 isolates ofClostridium perfringensfrom food poisoning outbreaks and a variety of other sources. It was found that strains of the same serotype within an outbreak showed similar patterns of susceptibility to bacteriocins, and the use of a ‘one difference’ rule is proposed for interpretation of the typing patterns of epidemiologically related strains. Isolates of different serotype or of the same serotype isolated from different sources produced many variations in bacteriocin susceptibility patterns.Two computer programs were developed to assist in the interpretation of bacteriocin typing patterns. Their use showed that related and unrelated strains formed different clusters and enabled a range of the 20 most discriminatory bacteriocins to be selected.Isolates ofC. perfringensfrom a wide range of sources were screened for their ability to produce bacteriocins. A much greater proportion of the strains from food poisoning outbreaks was bacteriocinogenic than were isolates from human and animal infections, various foods and the environment. The relevance of these findings to the occurrence ofC. perfringensfood poisoning is discussed.
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Fagheei Aghmiyuni, Zeinab, Horieh Saderi, Parviz Owlia, and Navid Saidi. "Evaluation of the Effect of Lactobacillus acidophilus ATCC 4356 Bacteriocin against Staphylococcus aureus." BioMed Research International 2024 (March 22, 2024): 1–5. http://dx.doi.org/10.1155/2024/4119960.
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Background. Lactobacillus acidophilus is lactic acid bacteria that produce bacteriocins. Bacteriocins are antimicrobial peptides or proteins that exhibit activity against closely related bacteria. The aim of this study was to determine the effect of L. acidophilus ATCC 4356 bacteriocin against Staphylococcus aureus. Material and Methods. We used four different phenotypic methods for antimicrobial activities against two standard strains: methicillin-resistant S. aureus (MRSA) ATCC 33591 and methicillin-susceptible S. aureus (MSSA) ATCC 25923. The methods were (1) agar well diffusion, (2) overlay soft agar, (3) paper disk, and (4) modification of punch hole. The ammonium sulfate method was used to concentrate crude bacteriocin, and ultrafiltration and dialysis tubes were used to remove ammonium sulfate from the bacteriocins. Each method was repeated in triplicate. Result. L. acidophilus ATCC 4356 showed antimicrobial activity against both MRSA and MSSA standard strains only by the overlay soft agar method and not by the agar well diffusion, punch hole modification, and paper disk methods. No antimicrobial effects were observed in crude bacteriocins concentrated. Conclusion. The growth inhibition of S. aureus in overlay soft agar method may be due to the production of bacteriocin-like substances. The overlay soft agar method is a qualitative test, so there is a need for further study to optimize the conditions for the production of bacteriocin-like substances in the culture supernatant and precise comparison between the inhibitory activity and pheromone secretion of different strains.
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Barbosa, Joana, Helena Albano, Beatriz Silva, Maria Helena Almeida, Teresa Nogueira, and Paula Teixeira. "Characterization of a Lactiplantibacillus plantarum R23 Isolated from Arugula by Whole-Genome Sequencing and Its Bacteriocin Production Ability." International Journal of Environmental Research and Public Health 18, no. 11 (May 21, 2021): 5515. http://dx.doi.org/10.3390/ijerph18115515.
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Lactiplantibacillus plantarum is one of the lactic acid bacteria species most used as probiotics and starter cultures in food production. Bacteriocin-producers Lpb. plantarum are also promising natural food preservatives. This study aimed to characterize Lpb. plantarum R23 and its bacteriocins (R23 bacteriocins). The genome sequence of Lpb. plantarum R23 was obtained by whole-genome sequencing (WGS) in an Illumina NovaSeq platform. The activity of Lpb. plantarum R23-produced bacteriocin against two Listeria monocytogenes strains (L7946 and L7947) was evaluated, and its molecular size was determined by tricine-SDS-PAGE. No virulence or antibiotic resistance genes were detected. Four 100% identical proteins to the class II bacteriocins (Plantaricin E, Plantaricin F, Pediocin PA-1 (Pediocin AcH), and Coagulin A) were found by WGS analysis. The small (<6.5 kDa) R23 bacteriocins were stable at different pH values (ranging from 2 to 8), temperatures (between 4 and 100 °C), detergents (all, except Triton X-100 and Triton X-114 at 0.01 g/mL), and enzymes (catalase and α-amylase), did not adsorb to the producer cells, had a bacteriostatic mode of action and their maximum activity (AU/mL = 12,800) against two L. monocytogenes strains occurred between 15 and 21 h of Lpb. plantarum R23 growth. Lactiplantibacillus plantarum R23 showed to be a promising bio-preservative culture because, besides being safe, it produces a stable bacteriocin or bacteriocins (harbors genes encoding for the production of four) inhibiting pathogens as L. monocytogenes. Further studies in different food matrices are required to confirm this hypothesis and its suitability as a future starter culture.
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Fugaban, Joanna Ivy Irorita, Jorge Enrique Vazquez Bucheli, Wilhelm Heinrich Holzapfel, and Svetoslav Dimitrov Todorov. "Assessment of Bacteriocin-Antibiotic Synergy for the Inhibition and Disruption of Biofilms of Listeria monocytogenes and Vancomycin-Resistant Enterococcus." Microbiology Research 13, no. 3 (July 29, 2022): 480–99. http://dx.doi.org/10.3390/microbiolres13030033.
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In this study, we have evaluated the effects of previously characterized bacteriocins produced by E. faecium strains ST651ea, ST7119ea, and ST7319ea, against biofilm formation and biofilms formed by L. monocytogenes ATCC15313 and vancomycin-resistant E. faecium VRE19. The effects of bacteriocins on the biofilms formed by L. monocytogenes ATCC151313 were evaluated by crystal violet assay and further confirmed by quantifying viable cells and cell metabolic activities through flow cytometry and TTC assay, respectively, indicating that bacteriocin activities required to completely eradicate biofilms are at least 1600 AU mL−1, 3200 AU mL−1, and 6400 AU mL−1, respectively for each bacteriocin evaluated. Furthermore, bacteriocins ST651ea and ST7119ea require at least 6400 AU mL−1 to completely eradicate the viability of cells within the biofilms formed by E. faecium VRE19, while bacteriocin ST7319ea requires at least 12800 AU mL−1 to obtain the same observations. Assessment of synergistic activities between selected conventional antibiotics (ciprofloxacin and vancomycin) with these bacteriocins was carried out to evaluate their effects on biofilm formation and pre-formed biofilms of both test microorganisms. Results showed that higher concentrations are needed to completely eradicate metabolic activities of cells within pre-formed biofilms in contrast with the biofilm formation abilities of the strains. Furthermore, synergistic activities of bacteriocins with both ciprofloxacin and vancomycin are more evident against vancomycin-resistant E. faecium VRE19 rather than L. monocytogenes ATCC15313. These observations can be further explored for possible applications of these combinations of antibiotics as a possible treatment of clinically relevant pathogens.
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Abdullayeva, A. M., L. P. Blinkova, D. I. Udavliyev, Ch K. Avylov, and Yu D. Pakhomov. "METHODOLOGICAL TECHNIQUES FOR TEACHING THE WORK WITH ANTAGONISTIC BACTERIOCINPRODUCING MICROORGANISMS." Innovations and Food Safety, no. 3 (July 1, 2020): 58–63. http://dx.doi.org/10.31677/2311-0651-2019-25-3-58-63.
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The article sets out teaching methods for working with microbes - bacteriocin producers and with these substances. The Introduction of the article provides brief information about bacteriocins, which gives an idea of what are bacteriocins, that they are synthesized on ribosomes and why they can be an alternative to antibiotics. Such bacteriocin properties as antagonistic activity, non-toxicity and a sparing effect on the body, low frequency of resistant cell formation in microorganisms, the possibility of practical use of the substance for the treatment of infection or against bacterial contamination of food as preservatives are the motivation to study the secreted microorganisms for the ability to synthesize bacteriocin.
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Kojic, M., Jelena Lozo, Jelena Begovic, B. Jovcic, and Lj Topisirovic. "Characterization of lactococci isolated from homemade kefir." Archives of Biological Sciences 59, no. 1 (2007): 13–22. http://dx.doi.org/10.2298/abs0701013k.
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Five bacteriocin-producing lactococci isolates from traditionally prepared kefir were determined as Lactococcus lactis subsp. lactis. The analyzed isolates showed different plasmid profiles and no cross inhibition between them was detected. Moreover, natural isolate BGKF26 was resistant to the antimicrobial activity of nisin producing strain NP45. Plasmid curing experiments revealed that the genes encoding bacteriocin and proteinase production are located on separate genetic elements, except in BGKF26. Production of the tested bacteriocins depends on the concentration of casitone or triptone in the medium. Higher concentrations of casitone or triptone induce bacteriocin activity. Our DNA-DNA hybridization analyses suggest that the analyzed antimicrobial compounds probably are lactococcin-like bacteriocins.
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CESA-LUNACESA-LUNA, CATHERINE, JULIA-MARÍA ALATORRE-CRUZ, RICARDO CARREÑO-LÓPEZ, VERÓNICA QUINTERO-HERNÁNDEZ, and ANTONINO BAEZ. "Emerging Applications of Bacteriocins as Antimicrobials, Anticancer Drugs, and Modulators of The Gastrointestinal Microbiota." Polish Journal of Microbiology 70, no. 2 (June 2021): 143–59. http://dx.doi.org/10.33073/pjm-2021-020.
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The use of bacteriocins holds great promise in different areas such as health, food, nutrition, veterinary, nanotechnology, among others. Many research groups worldwide continue to advance the knowledge to unravel a novel range of therapeutic agents and food preservatives. This review addresses the advances of bacteriocins and their producer organisms as biocontrol agents for applications in the medical industry and agriculture. Furthermore, the bacteriocin mechanism of action and structural characteristics will be reviewed. Finally, the potential role of bacteriocins to modulate the signaling in host-associated microbial communities will be discussed.
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Salman, Mahwish, Shazia Anwer Bukhari, Muhammad Shahid, Tanzila Sahar, and Shazia Naheed. "Strain improvement of newly isolated Lactobacillus acidophilus MS1 for enhanced bacteriocin production." Turkish Journal of Biochemistry 43, no. 3 (September 13, 2017): 323–32. http://dx.doi.org/10.1515/tjb-2017-0075.
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Abstract Background: Lactic acid bacteria (LAB) are considered as GRAS (generally recognized as safe) and being used extensively as bio-preservatives. Bacteriocins, the metabolites of LAB, belong to a diverse family of naturally synthesized antimicrobial peptides. Objective: Strain improvement for enhanced bacteriocin production by physical and chemical mutagenesis. Methods: The bacterial strain was identified by 16S rDNA sequence analysis and improved by ultraviolet and ethidium bromide mutation. The resultant bacteriocin was biochemically characterized, purified and analyzed for mass determination. Results: Among mutants of identified Lactobacillus acidophilus MS1, the UV6 (ultraviolet mutant) revealed 3400 AU bacteriocin activity with 42% survival rate and EB5 (ethidium bromide mutant) exhibited 4020 AU with 28% survival rate. Bacteriocin of 6.5 kDa was purified by cation exchange and gel exclusion chromatography. It was found to be thermally stable at 100°C for 30 min and maintained the stability up to 121°C. The activity was monitored in a wide range of pH (4–9). Conclusion: Being resistant to several biochemical parameters, the bacteriocins have an effective incorporation in food, forage and pharmacy. There is a need to engage more efforts to explore novel bacteriocins and multifarious applications.
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Asarina, Shinta, Santi Sariasih, and Yuni Kulsum. "In silico Prediction of Bacteriocin Gene within the Genus of Lactobacillus." Jurnal Biologi Indonesia 18, no. 1 (2022): 103–10. http://dx.doi.org/10.47349/jbi/18012022/103.
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Lactobacillus is a genus that contains a high number of GRAS (Generally Recognized As Safe) species. Many bacteria strains among those species are of most importance in food microbiology and human nutrition due to their contribution in food fermentation as well as their probiotic role. Lactobacillus genus has long been associated with bacteriocin production and considered as promising antimicrobial agent. Nevertheless, Lactobacillus as a source of bacteriocins has not been fully explored. This study investigates this genus’s potential as a source of novel bacteriocins through the use of in silico screening software BAGEL4, which scans publicly available genomes for potential bacteriocin gene. The association of bacteriocin gene presence with phylogenetic position within the genus was examined. A number of candidates from multiple bacteriocin classes were also identified.