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1.
Meat Sci ; 183: 108661, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34467880

RESUMO

The increasing concern of consumers about food quality and safety and their rejection of chemical additives has promoted the breakthrough of the biopreservation field and the development of studies on the use of beneficial bacteria and their metabolites as potential natural antimicrobials for shelf life extension and enhanced food safety. Control of foodborne pathogens in meat and meat products represents a serious challenge for the food industry which can be addressed through the intelligent use of bio-compounds or biopreservatives. This article aims to systematically review the available knowledge about biological strategies based on the use of lactic acid bacteria to control the proliferation of undesirable microorganisms in different meat products. The outcome of the literature search evidenced the potential of several strains of lactic acid bacteria and their purified or semi-purified antimicrobial metabolites as biopreservatives in meat products for achieving longer shelf life or inhibiting spoilage and pathogenic bacteria, especially when combined with other technologies to achieve a synergistic effect.


Assuntos
Conservação de Alimentos/métodos , Lactobacillales/fisiologia , Produtos da Carne/microbiologia , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bacteriocinas/farmacologia , Microbiologia de Alimentos , Lactobacillales/metabolismo , Produtos da Carne/análise
2.
Food Chem ; 366: 130599, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34298392

RESUMO

Nisin was encapsulated in silica through sol-gel process by acid-catalyzed routes. The silica xerogels were characterized through nitrogen adsorption isotherms, small-angle X-ray scattering (SAXS), zeta potential, X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and Fourier transform infrared spectroscopy (FTIR). SAXS results showed that the particle diameters in a second level of aggregation varied from 4.78 to 5.86 nm. Zeta potential of silica particles were from -9.6 to -25.3 mV, while the surface area and pore diameters ranged from 216 to 598 m2 g-1 and 2.53 to 2.90 nm, respectively, indicating the formation of mesoporous nanostructures. Nisin retained the antimicrobial activity against all microorganisms tested after encapsulation in silica materials. These novel silica-based structures can be valuable carriers for nisin delivery in food systems.


Assuntos
Bacteriocinas , Nisina , Espalhamento a Baixo Ângulo , Dióxido de Silício , Difração de Raios X
3.
Food Res Int ; 149: 110658, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600660

RESUMO

Microbiological safety in food industry are always a concern regarding sublethal tolerance in bacteria for common and natural sanitizers. Natural bacteriocins, such as nisin (NIS), may negatively interfere in the efficiency of major compounds of essential oils against foodborne pathogenic bacteria. However, nanoemulsioned forms increase the bactericidal potential of natural compounds acting synergistically. In this study, cinnamaldehyde (CIN), citral (CIT), and linalool (LIN) were evaluated independently, associated with NIS, and in nanoemulsions (NEs) against Bacillus cereus using untargeted-metabolomics. Results revealed morphological changes in the structure of B. cereus treated with NEs of CIN and CIT, both NIS-associated. In addition, sensibility tests and UHPLC-QTOF-MS analyses indicated that NIS might react together with CIT reducing the bactericidal efficiency, while the nanoemulsion of CIT effect was enhanced by NIS in nanoemulsioned forms. This study highlights the importance of prudent administration of natural compounds as antimicrobial agents to prevent sublethal tolerance in pathogenic bacteria.


Assuntos
Bacteriocinas , Óleos Voláteis , Antibacterianos/farmacologia , Bacillus cereus , Metabolômica , Óleos Voláteis/farmacologia
4.
Food Res Int ; 149: 110699, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600693

RESUMO

Protective bacterial cultures (PCs) are commercially available to producers to control undesirable microbes in foods, including foodborne pathogens such as Listeria monocytogenes. They are generally recognized as safe for consumption and many are capable of producing bacteriocins. Yet their potential to act as probiotics and confer a health benefit on the host is not known. This study investigated the ability of three commercial PCs to survive human gastrointestinal conditions and exert anti-infective properties against L. monocytogenes. Counts of two PCs of Lactiplantibacillus plantarum remained unchanged after exposure to simulated gastrointestinal conditions, whereas counts of the PC Lactococcus lactis subsp. lactis were reduced by 5.3 log CFU/mL. Cultures of Lactiplantibacillus plantarum and Lactococcus lactis subsp. lactis adhered to human Caco-2 epithelial cells at âˆ¼ 6 log CFU/mL. This pretreatment reduced subsequent L. monocytogenes adhesion and invasion by 1-1.6 log CFU/mL and 3.8-4.9 log CFU/mL, respectively, compared to control. L. monocytogenes-induced cytotoxicity was also reduced from 29.1% in untreated monolayers to âˆ¼ 8% in those treated with PCs. Pretreatment of Caco-2 monolayers with Lactococcus lactis subsp. lactis and one PC of Lactiplantibacillus plantarum reduced L. monocytogenes translocation by ≥ 1.2 log CFU/mL compared to control (≥ 94.5% inhibition). All PCs significantly reduced DextranFITC permeability through Caco-2 monolayers to approximately half that of control. Pretreatment with PCs also reduced L. monocytogenes-induced mortality in Caenorhabditis elegans. These findings demonstrate the potential for commercially produced PCs to exert probiotic effects in the host through protection against L. monocytogenes infection, thus providing an additional benefit to food safety beyond inhibiting pathogen growth, survival, and virulence in foods.


Assuntos
Bacteriocinas , Listeria monocytogenes , Probióticos , Células CACO-2 , Microbiologia de Alimentos , Humanos
5.
Int J Mol Sci ; 22(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34638967

RESUMO

The objective of this work was to develop a chitosan/agar-agar bioplastic film incorporated with bacteriocin that presents active potential when used as food packaging. The formulation of the film solution was determined from an experimental design, through the optimization using the desirability function. After establishing the concentrations of the biopolymers and the plasticizer, the purified bacteriocin extract of Lactobacillus sakei was added, which acts as an antibacterial agent. The films were characterized through physical, chemical, mechanical, barrier, and microbiological analyses. The mechanical properties and water vapor permeability were not altered by the addition of the extract. The swelling property decreased with the addition of the extract and the solubility increased, however, the film remained intact when in contact with the food, thus allowing an efficient barrier. Visible light protection was improved by increased opacity and antibacterial capacity was effective. When used as Minas Frescal cream cheese packaging, it contributed to the increase of microbiological stability, showing a reduction of 2.62 log UFC/g, contributing a gradual release of the active compound into the food during the storage time. The film had an active capacity that could be used as a barrier to the food, allowing it to be safely packaged.


Assuntos
Antibacterianos/química , Bacteriocinas/química , Plásticos Biodegradáveis/química , Biopolímeros/química , Embalagem de Alimentos/métodos , Ágar/química , Materiais Biocompatíveis/química , Queijo/microbiologia , Quitosana/química , Temperatura Alta , Lactobacillus sakei/química , Lactobacillus sakei/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Permeabilidade , Extratos Vegetais/química , Plastificantes/química , Rodófitas/química , Solubilidade , Vapor
6.
Elife ; 102021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664551

RESUMO

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an important emerging zoonotic pathogen that causes severe skin infections. To combat infections from drug-resistant bacteria, the transplantation of commensal antimicrobial bacteria as a therapeutic has shown clinical promise. We screened a collection of diverse staphylococcus species from domestic dogs and cats for antimicrobial activity against MRSP. A unique strain (S. felis C4) was isolated from feline skin that inhibited MRSP and multiple gram-positive pathogens. Whole genome sequencing and mass spectrometry revealed several secreted antimicrobials including a thiopeptide bacteriocin micrococcin P1 and phenol-soluble modulin beta (PSMß) peptides that exhibited antimicrobial and anti-inflammatory activity. Fluorescence and electron microscopy revealed that S. felis antimicrobials inhibited translation and disrupted bacterial but not eukaryotic cell membranes. Competition experiments in mice showed that S. felis significantly reduced MRSP skin colonization and an antimicrobial extract from S. felis significantly reduced necrotic skin injury from MRSP infection. These findings indicate a feline commensal bacterium that could be utilized in bacteriotherapy against difficult-to-treat animal and human skin infections.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bacteriocinas/farmacologia , Farmacorresistência Bacteriana , Infecções Estafilocócicas/veterinária , Staphylococcus/química , Staphylococcus/efeitos dos fármacos , Animais , Antibacterianos/química , Anti-Infecciosos/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Bacteriocinas/química , Gatos/microbiologia , Espectrometria de Massas , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Sequenciamento Completo do Genoma
7.
Appl Microbiol Biotechnol ; 105(20): 7857-7869, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34554273

RESUMO

Alternative strategies to antibiotic treatment are required to inhibit pathogens, including Staphylococcus aureus. Bacteriocins, such as the lantibiotic bovicin HC5, have shown potential to control pathogens. This study aims to evaluate the stress response of S. aureus to bovicin HC5 using a proteomic approach. Sublethal concentrations of the bacteriocin repressed the synthesis of 62 cytoplasmic proteins, whereas 42 proteins were induced in S. aureus COL. Specifically, synthesis of several proteins involved in amino acid biosynthesis, mainly products of ilv-leu operon, and DNA metabolism, such as DNA polymerase I, decreased following bovicin treatment while proteins involved in catabolism, mainly tricarboxylic acid cycle metabolism, and chaperones were over-expressed. The levels of CodY and CcpA, important regulators involved in the stationary phase adaptation and catabolite repression, respectively, also increased in the presence of the bacteriocin. These results indicate that stress caused by the sublethal concentration of bovicin HC5 in the cell membrane results in growth reduction, reduced protein synthesis, and, at the same time, enhanced the levels of chaperones and enzymes involved in energy-efficient catabolism in an attempt to restore energy and cell homeostasis. These results bring relevant information to amplify the knowledge concerning the bacterial physiological changes in response to the stress caused by the cell exposition to bovicin HC5. New potential targets for controlling this pathogen can also be determined from the new protein expression pattern presented. KEY POINTS: • Bovicin HC5 changed the synthesis of cytoplasmic proteins of S. aureus. • Bovicin HC5 interfered in the synthesis of proteins of amino acids biosynthesis. • Synthesis of chaperones enhanced in the presence of sublethal dosage of bovicin HC5.


Assuntos
Bacteriocinas , Antibacterianos/farmacologia , Membrana Celular , Proteômica , Staphylococcus aureus
8.
Toxicon ; 202: 67-74, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34571097

RESUMO

Consuming cooked meat contaminated with bacteria that carry thermostable hemolytic exopolysaccharide (ESP), could lead to severe diseases. Culture of a 5- h boiled sample of meat goulash on blood agar showed growth of a gram positive rod-shaped, mucoid and hemolytic bacterium. Biochemical tests and amplification of 1500 bp product of 16S rDNA and sequencing revealed bacterial identity as Weissella confusa. After 1 h boiling of bacterial suspension, they were alive and hemolytic, increased in volume and aggregated. After 8 h boiling of bacterial suspension with coverslip, live bacteria showed hemolysis, clustered and adhered to coverslip. Bacterial bacteriocin and hemolytic activities remained unchanged upon autoclaving. Purified bacterial EPS retained hemolytic activity after autoclaving. Boiling contaminated meat had no negative impact on viability of heat-stable W. confusa and its hemolytic EPS. Thermostable hemolytic EPS protected W. confusa from excessive heat. Hygienic practice in butcheries and kitchens are necessary to eliminate bacterial contaminants.


Assuntos
Temperatura Alta , Carne/microbiologia , Polissacarídeos Bacterianos , Weissella , Bactérias , Bacteriocinas , Contaminação de Alimentos , Microbiologia de Alimentos , Weissella/isolamento & purificação
9.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34544866

RESUMO

Genome evolution is an essential and stringently regulated aspect of biological fitness. For bacteria, natural competence is one of the principal mechanisms of genome evolution and is frequently subject to multiple layers of regulation derived from a plethora of environmental and physiological stimuli. Here, we present a regulatory mechanism that illustrates how such disparate stimuli can be integrated into the Streptococcus mutans natural competence phenotype. S. mutans possesses an intriguing, but poorly understood ability to coordinately control its independently regulated natural competence and bacteriocin genetic pathways as a means to acquire DNA released from closely related, bacteriocin-susceptible streptococci. Our results reveal how the bacteriocin-specific transcription activator BrsR directly mediates this coordination by serving as an anti-adaptor protein responsible for antagonizing the proteolysis of the inherently unstable, natural competence-specific alternative sigma factor ComX. This BrsR ability functions entirely independent of its transcription regulator function and directly modulates the timing and severity of the natural competence phenotype. Additionally, many of the DNA uptake proteins produced by the competence system were surprisingly found to possess adaptor abilities, which are employed to terminate the BrsR regulatory circuit via negative feedback. BrsR-competence protein heteromeric complexes directly inhibit nascent brsR transcription as well as stimulate the Clp-dependent proteolysis of extant BrsR proteins. This study illustrates how critical genetic regulatory abilities can evolve in a potentially limitless variety of proteins without disrupting their conserved ancestral functions. These unrecognized regulatory abilities are likely fundamental for transducing information through complex genetic networks.


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriocinas/metabolismo , Regulação Bacteriana da Expressão Gênica , Mapas de Interação de Proteínas , Streptococcus mutans/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Streptococcus mutans/genética , Streptococcus mutans/crescimento & desenvolvimento , Fatores de Transcrição/genética
10.
Elife ; 102021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34488940

RESUMO

Bacteria inhibit and kill one another with a diverse array of compounds, including bacteriocins and antibiotics. These attacks are highly regulated, but we lack a clear understanding of the evolutionary logic underlying this regulation. Here, we combine a detailed dynamic model of bacterial competition with evolutionary game theory to study the rules of bacterial warfare. We model a large range of possible combat strategies based upon the molecular biology of bacterial regulatory networks. Our model predicts that regulated strategies, which use quorum sensing or stress responses to regulate toxin production, will readily evolve as they outcompete constitutive toxin production. Amongst regulated strategies, we show that a particularly successful strategy is to upregulate toxin production in response to an incoming competitor's toxin, which can be achieved via stress responses that detect cell damage (competition sensing). Mirroring classical game theory, our work suggests a fundamental advantage to reciprocation. However, in contrast to classical results, we argue that reciprocation in bacteria serves not to promote peaceful outcomes but to enable efficient and effective attacks.


Assuntos
Antibacterianos/biossíntese , Bacteriocinas/metabolismo , Guerra Biológica , Percepção de Quorum , Fenômenos Fisiológicos Bacterianos , Evolução Biológica
11.
Eur J Pharm Sci ; 166: 105990, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481880

RESUMO

Superficial infections in chronic wounds can prevent the wound healing process by the development of persistent infections and drug-resistant biofilms. Topically applied antimicrobial formulations with stabilized and controlled release offer significant benefits for the effective treatment of wound infections. Bacteriocins are the antimicrobial peptides (AMPs) produced by bacteria that are viable alternatives to antibiotics owing to their natural origin and low propensity for resistance development. Herein, we developed a hybrid hydrogel composed of Pluronic F127 (PF127), ethylenediaminetetraacetic acid (EDTA) loaded liposomes, glutathione (GSH), and the bacteriocin Garvicin KS (GarKS) referred to as "GarKS gel". The GarKS gel exhibited suitable viscosity and rheological properties along with controlled release behavior (up to 9 days) for effective peptide delivery following topical application. Potent in vitro antibacterial and anti-biofilm effects of GarKS gel were evident against the Gram-positive bacterium Staphylococcus aureus. The in vivo treatment of methicillin resistant S. aureus (MRSA) infected mouse wounds suggested potent antibacterial effects of the GarKS gel following multiple applications of once-a-day application for three consecutive days. Altogether, these results provide proof-of-concept for the successful development of AMP loaded topical formulation for effective treatment of wound infections.


Assuntos
Bacteriocinas , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Infecção dos Ferimentos , Animais , Antibacterianos , Hidrogéis , Camundongos , Infecções Estafilocócicas/tratamento farmacológico , Infecção dos Ferimentos/tratamento farmacológico
12.
PLoS One ; 16(9): e0251951, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34473709

RESUMO

The purpose of this study was to explore potential mechanisms of cytotoxicity towards HeLa and HT29 cells displayed by Pediocin PA-1. We did this by carrying out sequence alignments and 3D modelling of related bacteriocins which have been studied in greater detail: Microcin E492, Enterocin AB heterodimer and Divercin V41. Microcin E492 interacts with Toll-Like Receptor 4 in order to activate an apoptosis reaction, sequence alignment showed a high homology between Pediocin PA-1 and Microcin E492 whereas 3D modelling showed Pediocin PA-1 interacting with TLR-4 in a way reminiscent of Microcin E492. Furthermore, Pediocin PA-1 had the highest homology with the Enterocin heterodimer, particularly chain A; Enterocin has also shown to cause an apoptotic response in cancer cells. Based on this we are led to strongly believe Pediocin PA-1 interacts with TLRs in order to cause cell death. If this is the case, it would explain the difference in cytotoxicity towards HeLa over HT29 cells, due to difference in expression of particular TLRs. Overall, we believe Pediocin PA-1 exhibits a dual effect which is dose dependant, like that of Microcin. Unfortunately, due to the COVID-19 pandemic, we were unable to carry out experiments in the lab, and the unavailability of important data meant we were unable to provide and validate out solid conclusions, but rather suggestions. However, bioinformatic analysis is still able to provide information regarding structure and sequence analysis to draw plausible and evidence based conclusions. We have been able to highlight interesting findings and how these could be translated into future research and therapeutics in order to improve the quality of treatment and life of cancer patients.


Assuntos
Bacteriocinas/química , Bacteriocinas/farmacologia , Pediocinas/química , Pediocinas/farmacologia , Conformação Proteica , Sequência de Aminoácidos , Antibacterianos/química , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Bacteriocinas/genética , Hidrocarbonetos Aromáticos com Pontes/química , Hidrocarbonetos Aromáticos com Pontes/farmacologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , Sobrevivência Celular/efeitos dos fármacos , Células HT29 , Células HeLa , Humanos , Modelos Moleculares , Pandemias , Pediocinas/genética , SARS-CoV-2/fisiologia , Homologia de Sequência de Aminoácidos , Receptor 4 Toll-Like/metabolismo
13.
Obes Res Clin Pract ; 15(5): 499-505, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34474970

RESUMO

BACKGROUND AND OBJECTIVE: The problem of obesity and its related complications are adversely affecting human society. We studied the effects of gassericin A, a bacteriocin produced by the intestinal bacteria, on adipocyte differentiation and development. DESIGN: Gassericin A was purified from Lactobacillus gasseri LA39 and was added to the culture medium of 3T3-L1 cells in two phases: Phase 1, 3T3-L1 cells were incubated with gassericin A while being induced to adipocytes (days 1-7); phase 2, the cells were incubated with the bacteriocin after being induced to adipocytes (days 8-12). The resultant changes in the pattern of expression of some of the important genes involved in adipogenesis were evaluated by RT-qPCR. The viability of cells and their numbers were also studied. RESULTS: In phase 1 of the study, the levels of transcripts for stearoyl CoA desaturase (SCD-1), zinc finger protein 423 (zfp-423), and glucose transporter 4 (GLUT4) genes were significantly reduced, while that of 422ap2 gene showed a significant increment (p < 0.05). In phase 2, the zfp-423 gene showed a reduction of expression and the 422ap2 gene showed an increase in expression (p < 0.05). The other genes including UCP-1 and TNF-α did not show any significant changes in neither of the groups. Gassericin A did not affect the morphology or viability of the cells, however, the numbers of cells had nearly doubled in the treatment groups. CONCLUSION: It seems that gassericin A could significantly alter the properties of adipocytes while they are in the process of development and after they have developed.


Assuntos
Adipócitos/efeitos dos fármacos , Bacteriocinas , Células 3T3-L1 , Adipogenia , Animais , Bacteriocinas/farmacologia , Diferenciação Celular , Camundongos , Obesidade/terapia
14.
Appl Microbiol Biotechnol ; 105(18): 6921-6930, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34476515

RESUMO

Bacteriocins derived from lactic acid bacteria (LAB) are well recognized as promising food preservative due to high safety and potent antibacterial activity against foodborne pathogens and spoilage bacteria. In this study, an antimicrobial agent-producing strain FZU63 from Chinese sauerkraut was identified as Lactobacillus coryniformis based on physio-biochemical characterization and 16S rDNA sequence analysis. In addition, a bacteriocin was purified from the culture supernatant of L. coryniformis FZU63, and its molecular mass was determined as 1493.709 Da. Moreover, the amino acid sequence of the bacteriocin was predicted to be RQQPMTLDYRW-NH2 using nanoliter/microliter liquid chromatography combined with triple quadrupole-linear ion trap tandem mass spectrometry and was named as Lactocin 63. Furthermore, Lactocin 63 displays potent antimicrobial activity against the tested Gram-positive and negative bacteria based on the results of determining MICs. Subsequently, the action mode of Lactocin 63 against Shewanella putrefaciens was investigated. The results demonstrated that Lactocin 63 targets and is adsorbed onto the bacterial cell wall and membrane and then disrupts cytoplasmic membrane, which is leading to leakage of cytoplasm according to the results of flow cytometry analysis and the observation of cellular ultra-structure using confocal laser microscopy and atomic force microscopy. Collectively, these results are helpful and providing the theoretical base for developing and applying LAB-derived bacteriocins as promising bio-preservatives to combat foodborne pathogens and spoilage bacteria in seafood industries.Key points• A bacteriocin-producing strain Lactobacillus coryniformis was isolated.• A novel bacteriocin produced by Lactobacillus coryniformis FZU63 was characterized.• Action mechanism of the bacteriocin against S. putrefaciens was elucidated in vitro.


Assuntos
Anti-Infecciosos , Bacteriocinas , Shewanella putrefaciens , Antibacterianos/farmacologia , Bacteriocinas/genética , Bacteriocinas/farmacologia , Lactobacillus
15.
J Agric Food Chem ; 69(36): 10741-10748, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34478301

RESUMO

Plantaricin Q7 is a bacteriocin produced by Lactobacillus plantarum Q7 with food preservation potential. Low yield is one of the bottlenecks of the wide application of plantaricin Q7. Nontargeted metabolomics was performed to reveal the mechanism of plantaricin Q7 biosynthesis. The results showed that the composition and abundance of intracellular metabolites varied significantly at key time points of plantaricin Q7 synthesis. Differential metabolic pathways were purine metabolism; pyrimidine metabolism; alanine, aspartate, and glutamate metabolism; amino acid biosynthesis; aminoacyl-tRNA biosynthesis; and ABC transporters. Differential metabolites were xanthine, deoxyadenosine, uracil, 5-methylcytosine, α-ketoglutarate, γ-aminobutyric acid, glutamate, glutamine, and tryptophan. Based on metabolomics information, the putative metabolic synthesis pathway of plantaricin Q7 was proposed. Glutamine, glutamate, and 5-methylcytosine could be critical metabolites and simulate plantaricin Q7 biosynthesis significantly (P < 0.05). Bacteriocin production was investigated by comparative metabolomics in this report, which could help to achieve higher plantaricin Q7 yield by metabolic regulation.


Assuntos
Bacteriocinas , Lactobacillus plantarum , Bacteriocinas/metabolismo , Vias Biossintéticas , Conservação de Alimentos , Lactobacillus plantarum/metabolismo , Metabolômica
16.
Pol J Microbiol ; 70(2): 143-159, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34349808

RESUMO

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.


Assuntos
Anti-Infecciosos , Antineoplásicos , Bacteriocinas , Microbioma Gastrointestinal , Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Bacteriocinas/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbiota/fisiologia , Controle Biológico de Vetores/tendências , Transdução de Sinais
17.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360927

RESUMO

A 98.1 Kb genomic region from B. pumilus 15.1, a strain isolated as an entomopathogen toward C. capitata, the Mediterranean fruit fly, has been characterised in search of potential virulence factors. The 98.1 Kb region shows a high number of phage-related protein-coding ORFs. Two regions with different phylogenetic origins, one with 28.7 Kb in size, highly conserved in Bacillus strains, and one with 60.2 Kb in size, scarcely found in Bacillus genomes are differentiated. The content of each region is thoroughly characterised using comparative studies. This study demonstrates that these two regions are responsible for the production, after mitomycin induction, of a phage-like particle that packages DNA from the host bacterium and a novel phage for B. pumilus, respectively. Both the phage-like particles and the novel phage are observed and characterised by TEM, and some of their structural proteins are identified by protein fingerprinting. In addition, it is found that the phage-like particle shows bacteriocin activity toward other B. pumilus strains. The effect of the phage-like particles and the phage in the toxicity of the strain toward C. capitata is also evaluated.


Assuntos
Bacillus pumilus , Bacteriocinas/metabolismo , Bacteriófagos , Ceratitis capitata/microbiologia , Fatores de Virulência/metabolismo , Animais , Bacillus pumilus/isolamento & purificação , Bacillus pumilus/patogenicidade , Bacillus pumilus/virologia , Bacteriófagos/patogenicidade , Bacteriófagos/fisiologia
18.
Theriogenology ; 173: 163-172, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34416447

RESUMO

The conventional storage temperature of 16-18 °C provides optimal conditions for the preservation of boar sperm quality, which are extremely cold sensitive cells. On the other hand, however, it requires the addition of antibiotics to inhibit bacterial growth. Rising numbers of antibiotic resistant bacteria call for alternatives to this conventional storing method. As potential alternative, three different bacteriocin candidates with known bacteriolytic activity against E. coli were examined on possible negative effects concerning the sperm quality and on their impact on bacterial growth of E. coli ILSH 02692 in BTS-extended semen w/o antibiotics. Although the lower concentrations (0.01 and 0.25%) of all bacteriocins did not show any impact on the quality of the semen, the higher concentrations (0.5 and 1.0%) of two bacteriocins led to a significant (P < 0.05) reduction in several sperm quality characteristics. The bacteriocin 860/1c after AMS/dialysis did not affect the sperm quality in any of the tested concentrations and in all tested extenders (BTS, MIII, Androstar Premium and Androhep all w/o antibiotics) at 16 °C as well as at 6 °C. This bacteriocin reduced growth of E. coli ILSH 02692 in BTS-extended semen by 50% compared to the control w/o bacteriocin. Furthermore, a preliminary insemination trial indicated no impact of the selected bacteriocin on fertility. These promising results show that the application of bacteriocins in liquid-preserved semen is a feasible possibility in the future.


Assuntos
Bacteriocinas , Preservação do Sêmen , Animais , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Escherichia coli , Masculino , Preservação do Sêmen/veterinária , Espermatozoides , Suínos
19.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445321

RESUMO

Listeria monocytogenes is an important food-borne pathogen and a serious concern to food industries. Bacteriocins are antimicrobial peptides produced naturally by a wide range of bacteria mostly belonging to the group of lactic acid bacteria (LAB), which also comprises many strains used as starter cultures or probiotic supplements. Consequently, multifunctional strains that produce bacteriocins are an attractive approach to combine a green-label approach for food preservation with an important probiotic trait. Here, a collection of bacterial isolates from raw cow's milk was typed by 16S rRNA gene sequencing and MALDI-Biotyping and supernatants were screened for the production of antimicrobial compounds. Screening was performed with live Listeria monocytogenes biosensors using a growth-dependent assay and pHluorin, a pH-dependent protein reporting membrane damage. Purification by cation exchange chromatography and further investigation of the active compounds in supernatants of two isolates belonging to the species Pediococcus acidilactici and Lactococcus garvieae suggest that their antimicrobial activity is related to heat-stable proteins/peptides that presumably belong to the class IIa bacteriocins. In conclusion, we present a pipeline of methods for high-throughput screening of strain libraries for potential starter cultures and probiotics producing antimicrobial compounds and their identification and analysis.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Descoberta de Drogas/métodos , Listeria monocytogenes/efeitos dos fármacos , Probióticos , Animais , Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Lactococcus/isolamento & purificação , Lactococcus/metabolismo , Microbiota , Leite/microbiologia , Pediococcus acidilactici/isolamento & purificação , Pediococcus acidilactici/metabolismo
20.
Appl Microbiol Biotechnol ; 105(18): 6735-6748, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34453561

RESUMO

Staphylococci belong to conditionally pathogenic bacteria, and the pathogenicity of Staphylococcus aureus is the strongest among them. Enterotoxin produced by it can contaminate food and cause food poisoning. Bacteriocin is a kind of polypeptide with antibacterial activity synthesized by some bacteria during metabolism. In this study, we report on purification, characterization, and mode of action of the bacteriocin named Paracin 54, produced by Lactobacillus paracasei ZFM54. Paracin 54 was purified by precipitation with 80% ammonium sulfate, strong cation-exchange chromatography, G-25 gel column, and reversed-phase high-performance liquid chromatography (HPLC). The molecular weight of Paracin 54 (5718.1843 Da) was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Paracin 54 showed broad-spectrum inhibitory activity. It had a strong inhibitory effect on Staphylococci with minimum inhibitory concentration values of 3.00-4.50 µg/mL. Paracin 54 was heat-stable and active only in acidic pH range (2-6). After treatment with proteases, the activity was lost. The results of mode of action showed Paracin 54 damaged the cell membrane and cell wall of Staphylococcus aureus, and then the cytoplasm leaked out, leading to death of the bacteria. These properties make Paracin 54 a promising candidate to prevent the growth of spoilage bacteria and control food poisoning caused by Staphylococci. KEY POINTS: • Paracin 54 was purified from Lactobacillus paracasei ZFM54 with good biochemical characteristics. • Paracin 54 had a strong effect against Staphylococci, making it a promising preservative to prevent the growth of Staphylococci in food. • The mode of action of Paracin 54 on Staphylococcus aureus was revealed.


Assuntos
Bacteriocinas , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Testes de Sensibilidade Microbiana , Peso Molecular , Staphylococcus
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