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Drug Discoveries & Therapeutics May 2022Antimicrobial peptides (AMPs) are inherently occurring proteins that are produced by microorganisms as secondary metabolites. Members of genus Bacillus produce many... (Review)
Review
Antimicrobial peptides (AMPs) are inherently occurring proteins that are produced by microorganisms as secondary metabolites. Members of genus Bacillus produce many types of AMPs by ribosomal (bacteriocins) and non-ribosomal (polymyxins and iturins) mechanisms. Bacteriocins are ribosomally synthesized peptides that inhibit the growth of closely related bacterial strains. Moreover, bacteriocins produced by Bacillus species have been widely used in pharmaceutical, food industry, fishery, livestock as well as in agriculture sector. The objective of this review is to assess the characterization of the Bacillus-derived bacteriocins, their potential use in different sectors and structure-activity relationships.
Topics: Anti-Bacterial Agents; Bacillus; Bacteria; Bacteriocins; Structure-Activity Relationship
PubMed: 35466124
DOI: 10.5582/ddt.2021.01087 -
Microbiology and Molecular Biology... Jun 2006Many bacteria produce antimicrobial peptides, which are also referred to as peptide bacteriocins. The class IIa bacteriocins, often designated pediocin-like... (Review)
Review
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.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Bacteriocins; Forecasting; Models, Biological; Molecular Sequence Data; Sequence Homology, Amino Acid; Structure-Activity Relationship
PubMed: 16760314
DOI: 10.1128/MMBR.00016-05 -
Journal of Applied Microbiology Feb 2015To assess the antimicrobial properties of lactic acid bacteria from Tunisian raw bovine milk.
AIMS
To assess the antimicrobial properties of lactic acid bacteria from Tunisian raw bovine milk.
METHODS AND RESULTS
A bacteriocin-producing Enterococcus faecium strain was isolated from raw cow milk with activity against Gram-positive and Gram-negative bacteria. Antimicrobial substances produced by this strain were sensitive to proteolytic enzymes and were thermostable and resistant to a broad range of pH (2-10). Mode of action of antimicrobial substances was determined as bactericidal. Maximum activity was reached at the end of the exponential growth phase when checked against Listeria ivanovii BUG 496 (2366.62 AU ml(-1)). However, maximum antimicrobial activity against Pseudomonas aeruginosa 28753 was recorded at the beginning of the exponential growth phase. Enterococcus faecium GGN7 was characterized as free from virulence factors and was susceptible to tested antibiotics. PCR analysis of the micro-organism's genome revealed the presence of genes coding for enterocins A and B. Mass spectrometry analysis of RP-HPLC active fractions showed molecular masses corresponding to enterocins A (4835.77 Da) and B (5471.56 Da), and a peptide with a molecular mass of 3215.5 Da active only against Gram-negative indicator strains. The latter was unique in the databases.
CONCLUSIONS
Enterococcus faecium GGN7 produces three bacteriocins with different inhibitory spectra. Based on its antimicrobial properties and safety, Ent. faecium GGN7 is potentially useful for food biopreservation.
SIGNIFICANCE AND IMPACT OF THE STUDY
The results suggest the bacteriocins from GGN7 strain could be useful for food biopreservation.
Topics: Animals; Anti-Bacterial Agents; Bacteriocins; Enterococcus faecium; Milk
PubMed: 25413921
DOI: 10.1111/jam.12699 -
Journal of Dairy Science Sep 1994Leuconostoc spp. are lactic acid bacteria that are commonly associated with foods and that are used as starter bacteria in some dairy fermentations. Lactic acid bacteria... (Review)
Review
Leuconostoc spp. are lactic acid bacteria that are commonly associated with foods and that are used as starter bacteria in some dairy fermentations. Lactic acid bacteria are inhibitory to other bacteria because of pH, organic acids, hydrogen peroxide, and other chemicals produced during their growth, including bacteriocins. Bacteriocin production by Leuconostoc spp. was first observed in the 1950s, but only since 1984, when antagonistic activity of Leuconostoc spp. was reported, have more extensive studies of bacteriocins produced by Leuconostoc spp. been conducted, including mesentericin Y105, produced by Leuconostoc mesenteroides spp. mesenteroides; leucocin A-UAL 187, produced by Leuconostoc gelidum; carnosin 44A, produced by Leuconostoc carnosum; and leuconocin S, produced by Leuconostoc paramesenteroides. Bacteriocins produced by leuconostocs may or may not be active against other lactic acid bacteria, but all include Listeria in their activity spectra. Mesentericin Y105 is reported to be exclusively active against Listeria spp. The amino acid sequences for leucocin A and mesentericin Y105 have been determined. Despite considerable differences in antibacterial spectra, only two amino acids differ between these bacteriocins. The prevalence of leuconostocs in many adventitious fermentations of food and the use of leuconostocs as starter bacteria in controlled fermentations make the bacteriocins produced by these bacteria of interest as possible food preservatives by addition of the bacteriocin or its producer organism to foods.
Topics: Amino Acid Sequence; Bacteriocins; Leuconostoc; Molecular Sequence Data
PubMed: 7814741
DOI: 10.3168/jds.S0022-0302(94)77214-3 -
Brazilian Journal of Microbiology :... Apr 2019The bacteriocinogenic Enterococcus hirae ST57ACC recently isolated from a Brazilian artisanal cheese was subjected here to additional analyses in order to evaluate its...
The bacteriocinogenic Enterococcus hirae ST57ACC recently isolated from a Brazilian artisanal cheese was subjected here to additional analyses in order to evaluate its bacteriocin production and the potential influence of ABC transporter system in its expression. Besides these physiological and molecular aspects, the bacteriocin was evaluated for its cytotoxicity against HT-29. Differences in the inoculum size had no impact on the growth of E. hirae ST57ACC; however, the bacteriocin was only produced after 9 h of growth when the strain was inoculated at 5% or 10% (v/v), with similar levels of bacteriocin production obtained by both conventional growth and batch fermentation. Furthermore, potential expression of ABC transporters corresponding to the bacteriocin transport and sugar metabolism was identified. In terms of adverse effects, when a semi-purified fraction of the bacteriocin and the cell-free supernatant were tested against HT-29, total cell viability was similar to observed on untreated cells, indicating the absence of cytotoxic effect. Based on the obtained results, E. hirae ST57ACC can produce its bacteriocin at industrial level by using bioreactors, its bacteriocin expression is potentially influenced by the ABC transporter system, and no cytotoxic effects were observed on HT-29 cells, indicating its potential use as a bio-preservative.
Topics: ATP-Binding Cassette Transporters; Bacteriocins; Brazil; Carbohydrate Metabolism; Cell Line; Cheese; Enterococcus hirae; Food Preservatives; HT29 Cells; Humans
PubMed: 30852798
DOI: 10.1007/s42770-019-00068-4 -
Biocontrol Science Mar 2012Bacteriocins are ribosomally synthesized antibacterial peptides produced by bacteria that inhibit the growth of similar or closely related bacterial strains. A number of... (Review)
Review
Bacteriocins are ribosomally synthesized antibacterial peptides produced by bacteria that inhibit the growth of similar or closely related bacterial strains. A number of bacteriocins from a wide variety of bacteria have been discovered, and their diverse structures have been reported. Growing evidence suggests that bacteriocins have diverse structures, modes of action, mechanisms of biosynthesis and self-immunity, and gene regulation. Bacteriocins are considered as an attractive compound in food and pharmaceutical industries to prevent food spoilage and pathogenic bacterial growth. Furthermore, elucidation of their biosynthesis has led to the use of bacteriocin-controlled gene-expression systems and the biosynthetic enzymes of lantibiotics, a class of bacteriocins, as tools to design novel peptides. In this review, we summarize and discuss currently known information on bacteriocins produced by Gram-positive bacteria and their applications.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Bacteriocins; Drug Resistance, Bacterial; Molecular Sequence Data
PubMed: 22451427
DOI: 10.4265/bio.17.1 -
Microbiology Spectrum Aug 2022Infections caused by multiresistant pathogens have become a major problem in both human and veterinary medicine. Due to the declining efficacy of many antibiotics, new...
Infections caused by multiresistant pathogens have become a major problem in both human and veterinary medicine. Due to the declining efficacy of many antibiotics, new antimicrobials are needed. Promising alternatives or additions to antibiotics are bacteriocins, antimicrobial peptides of bacterial origin with activity against many pathogens, including antibiotic-resistant strains. From a sample of fermented maize, we isolated a Vagococcus fluvialis strain producing a bacteriocin with antimicrobial activity against multiresistant Enterococcus faecium. Whole-genome sequencing revealed the genes for a novel two-peptide lantibiotic. The production of the lantibiotic by the isolate was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, which revealed distinct peaks at 4,009.4 and 3,181.7 in separate fractions from reversed-phase chromatography. The combination of the two peptides resulted in a 1,200-fold increase in potency, confirming the two-peptide nature of the bacteriocin, named vagococcin T. The bacteriocin was demonstrated to kill sensitive cells by the formation of pores in the cell membrane, and its inhibition spectrum covers most Gram-positive bacteria, including multiresistant pathogens. To our knowledge, this is the first bacteriocin characterized from . Enterococci are common commensals in the intestines of humans and animals, but in recent years, they have been identified as one of the major causes of hospital-acquired infections due to their ability to quickly acquire virulence and antibiotic resistance determinants. Many hospital isolates are multiresistant, thereby making current therapeutic options critically limited. Novel antimicrobials or alternative therapeutic approaches are needed to overcome this global problem. Bacteriocins, natural ribosomally synthesized peptides produced by bacteria to eliminate other bacterial species living in a competitive environment, provide such an alternative. In this work, we purified and characterized a novel two-peptide lantibiotic produced by Vagococcus fluvialis LMGT 4216 isolated from fermented maize. The novel lantibiotic showed a broad spectrum of inhibition of Gram-positive strains, including vancomycin-resistant Enterococcus faecium, demonstrating its therapeutic potential.
Topics: Anti-Bacterial Agents; Bacteriocins; Enterococcaceae; Peptides; Vancomycin-Resistant Enterococci
PubMed: 35730941
DOI: 10.1128/spectrum.00954-22 -
Microbiology Spectrum Feb 2023Genome analysis of Corynebacterium lactis revealed a bacteriocin gene cluster encoding a putative bacteriocin of the linaridin family of ribosomally synthesized and...
Genome analysis of Corynebacterium lactis revealed a bacteriocin gene cluster encoding a putative bacteriocin of the linaridin family of ribosomally synthesized and posttranslationally modified peptides (RiPPs). The locus harbors typical linaridin modification enzymes but lacks genes for a decarboxylase and methyltransferase, which is unusual for type B linaridins. Supernatants of Corynebacterium lactis RW3-42 showed antimicrobial activity against Corynebacterium glutamicum. Deletion of the precursor gene clearly linked the antimicrobial activity of the producer strain to the identified gene cluster. Following purification, we observed potent activity of the peptide against , mainly other members of the genus , including the pathogenic species Corynebacterium striatum and Corynebacterium amycolatum. Also, low activity against some was observed, but there was no activity against Gram-negative species. The peptide is resilient towards heat but sensitive to proteolytic degradation by trypsin and proteinase K. Analysis by mass spectrometry indicates that corynaridin is processed by cleaving off the leader sequence at a conserved motif and posttranslationally modified by dehydration of all threonine and serin residues, resulting in a monoisotopic mass of 3,961.19 Da. Notably, time-kill kinetics and experiments using live biosensors to monitor membrane integrity suggest bactericidal activity that does not involve formation of pores in the cytoplasmic membrane. As species are ubiquitous in nature and include important commensals and pathogens of mammalian organisms, secretion of bacteriocins by species of this genus could be a hitherto neglected trait with high relevance for intra- and interspecies competition and infection. Bacteriocins are antimicrobial peptides produced by bacteria to fend off competitors in ecological niches and are considered to be important factors influencing the composition of microbial communities. However, bacteriocin production by bacteria of the genus has been a hitherto neglected trait, although its species are ubiquitous in nature and make up large parts of the microbiome of humans and animals. In this study, we describe and characterize a novel linaridin family bacteriocin from Corynebacterium lactis and show its narrow-spectrum activity, mainly against other actinobacteria. Moreover, we were able to extend the limited knowledge on linaridin bioactivity in general and for the first time describe the bactericidal activity of such a bacteriocin. Interestingly, the peptide, which was named corynaridin, appears bactericidal, but without formation of pores in the bacterial membrane.
Topics: Humans; Animals; Bacteriocins; Anti-Bacterial Agents; Corynebacterium; Peptides; Actinobacteria; Bacteria; Mammals
PubMed: 36541778
DOI: 10.1128/spectrum.01756-22 -
FEMS Microbiology Reviews Jan 2021In recent decades, bacteriocins have received substantial attention as antimicrobial compounds. Although bacteriocins have been predominantly exploited as food... (Review)
Review
In recent decades, bacteriocins have received substantial attention as antimicrobial compounds. Although bacteriocins have been predominantly exploited as food preservatives, they are now receiving increased attention as potential clinical antimicrobials and as possible immune-modulating agents. Infections caused by antibiotic-resistant bacteria have been declared as a global threat to public health. Bacteriocins represent a potential solution to this worldwide threat due to their broad- or narrow-spectrum activity against antibiotic-resistant bacteria. Notably, despite their role in food safety as natural alternatives to chemical preservatives, nisin remains the only bacteriocin legally approved by regulatory agencies as a food preservative. Moreover, insufficient data on the safety and toxicity of bacteriocins represent a barrier against the more widespread use of bacteriocins by the food and medical industry. Here, we focus on the most recent trends relating to the application of bacteriocins, their toxicity and impacts.
Topics: Anti-Infective Agents; Bacteriocins; Drug Development; Drug and Narcotic Control
PubMed: 32876664
DOI: 10.1093/femsre/fuaa039 -
Microbiology Spectrum Jun 2022Bacteriocins have been applied in the food industries and have become promising next-generation antibiotics. Some bacteria produce bacteriocins and possess immunity...
Bacteriocins have been applied in the food industries and have become promising next-generation antibiotics. Some bacteria produce bacteriocins and possess immunity factors for self-protection. Nisin A, a bacteriocin produced by Lactococcus lactis, shows broad-spectrum activity. However, the evolution and cross-resistance ability of the immunity factors in some species results in reduced susceptibility to bacteriocins. Here, we investigated the elements responsible for nisin A resistance in Streptococcus mutans and their contribution to mutacins (bacteriocins produced by S. mutans) resistance. We classified the nisin A-resistance regions into six types based on the different combinations of 3 immunity factors, and , and the presence of mutacin synthesis operon upstream of . Data shows that NsrX effectively acts against nisin A but not mutacins, while the newly identified ABC transporter MutHIJ acts against three mutacins but not nisin A. Three types of MutFEG are identified based on their amino acid sequences: α (in Nsr-types C and D-I), β (in Nsr-types B and d-III), and γ (in Nsr-type E). MutFEG-α strongly contributes to mutacin I resistance, while MutFEG-β and MutFEG-γ strongly contribute to mutacin III, IIIb, and nisin A resistance. Additionally, -like structures could be found in various streptococcal species isolated from the oral cavity of humans, chimpanzees, monkeys, bears, and hamsters. Our findings suggest that immunity factors rearrange and adapt in the presence of bacteriocins and could be transferred among closely related species, thus altering the bacterial competition within the microflora. Streptococcus mutans is an important organism of oral microbiota and associated with dental caries and systemic diseases such as stroke and endocarditis. They produce bacteriocins known as mutacins to compete with other oral bacteria and possess immune factors for self-protection. We found that the nisin A and mutacins resistance patterns correlated with the immunity components and MutFEG variants, and the genetic difference was driven by the insertion of mutacin-synthesis cassettes. Our study provides an understanding of the development of bacteriocin resistance among streptococcal species, which may alter the bacterial interaction and ecology within the oral biofilm.
Topics: Bacteriocins; Dental Caries; Gene Rearrangement; Humans; Immunologic Factors; Streptococcus; Streptococcus mutans
PubMed: 35604175
DOI: 10.1128/spectrum.01806-21