tenuazonic-acid and reutericyclin

Reutericyclin is an inhibitory compound produced by sourdough isolates of Lactobacillus reuteri that is structurally but not functionally related to naturally occurring tetramic acids. It is bacteriostatic or bactericidal to gram-positive bacteria based on its activity as a proton-ionophore, and a broad range of food-related spoilage organisms and pathogens is inhibited by reutericyclin. Gram-negative bacteria are resistant to reutericyclin because of the barrier properties of their outer membrane, and resistance of beer-spoiling lactobacilli towards hop bitter acids provides cross-protection to reutericyclin. Remarkably, reutericyclin-producing strains were shown to persist for a period of 10 years in an industrial sourdough fermentation, and reutericyclin was shown to be produced in concentrations active against competitors during growth of L. reuteri in sourdough. Based on the known properties of reutericyclin and L. reuteri, reutericyclin-producing strains may have applications in the biopreservation of foods. Furthermore, these strains were shown to colonize reconstituted lactobacilli-free mice at high levels. Therefore, they could serve as a suitable model system to evaluate a possible impact of antimicrobial compounds on the intestinal microflora of humans and animals.

Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Food Microbiology; Food Preservation; Gram-Negative Bacteria; Gram-Positive Bacteria; Lactobacillus; Microbial Sensitivity Tests; Pyrrolidinones; Tenuazonic Acid

Several sourdough lactic acid bacteria (LAB) produce inhibitory substances other than organic acids. Bacteriocins (bavaricin A, and plantaricin ST31), a bacteriocin-like inhibitory substance (BLIS C57), and a new antibiotic (reutericyclin) have been discovered. Maximum antimicrobial production was found in the pH range 4.0-6.0. Temperature optima vary strongly. The substances are resistant to heat and acidity, and inactivated by proteolytic enzymes, except for reutericyclin. Bavaricin A and plantaricin ST31 have been purified to homogeneity. Bavaricin A is classified as a class IIa bacteriocin. Reutericyclin is a new tetramic acid. The mode of action of bavaricin A, BLIS C57, and reutericyclin is bactericidal. Some of these substances are active towards some Bacilli, Staphylococci and Listeria strains. Up to now, only the application potential of purified bavaricin A has been examined. More research should be done to study the production, the activity, and the stability of these inhibitory substances in food systems as these often differ from the broths mostly used in this kind of studies. Furthermore, an extensive screening of the sourdough microflora must be performed, in particular towards Bacilli and fungi. This could lead to the discovery of additional inhibitory substances, although it seems that the frequency of isolating bacteriocin-producing sourdough LAB is low. However, potent antimicrobials towards Bacilli as well as antifungal substances will have to be found using rational screening strategies and novel purification and analytical techniques.

Topics: Anti-Bacterial Agents; Bacteriocins; Bread; Food Microbiology; Hydrogen-Ion Concentration; Lactobacillus; Microbial Sensitivity Tests; Temperature; Tenuazonic Acid

Streptococcus mutans is considered a primary etiologic agent of dental caries, which is the most common chronic infectious disease worldwide. S. mutans B04Sm5 was recently shown to produce reutericyclins and mutanocyclin through the

Topics: Biofilms; Dental Caries; Humans; Phylogeny; Streptococcus mutans; Tenuazonic Acid

We aimed to assess the in vitro antimicrobial activity and the in vivo effect on the murine fecal microbiome and volatile organic compound (VOC) profile of (S)-reutericyclin. The antimicrobial activity of (S)-reutericyclin was tested against

Topics: Animals; Discriminant Analysis; Feces; Male; Mice, Inbred BALB C; Microbial Sensitivity Tests; Microbiota; Tenuazonic Acid; Volatile Organic Compounds

The vaginal microbiota influences sexual transmission of human immunodeficiency virus type 1 (HIV-1). Colonization of the vaginal tract is normally dominated by

Topics: Animals; Antiviral Agents; Female; HIV-1; Humans; Lactobacillus; Laurates; Monoglycerides; Receptors, Virus; Tenuazonic Acid; Vagina; Viral Envelope Proteins; Virus Attachment; Virus Internalization; Viruses

Bacillus spp. cause ropy bread spoilage of bread, which is characterized by a rotten fruity odor, followed by discoloration and degradation of the crumb. Bacillus spp. are wheat grain endophytes and form heat resistant endospores, therefore, process hygiene and heating during baking do not prevent ropy spoilage. This study used 8 strains of Bacillus subtilis and Bacillus amyloliquefaciens to determine whether the presence and the copy number of spoVA

Topics: Amylases; Bacillus; Bacterial Proteins; Bread; DNA Copy Number Variations; Fermentation; Food Microbiology; Hydrogen-Ion Concentration; Limosilactobacillus reuteri; Microbial Viability; Operon; Spores, Bacterial; Temperature; Tenuazonic Acid

Human milk has antimicrobial compounds and immunomodulatory activities. We investigated glycerol monolaurate (GML) in human milk versus bovine milk and infant formula for antimicrobial and anti-inflammatory activities. Human milk contained approximately 3000 µg/ml of GML, compared to 150 μg/ml in bovine milk and none in infant formula. For bacteria tested (Staphylococcus aureus, Bacillus subtilis, Clostridium perfringens, Escherichia coli), except Enterococcus faecalis, human milk was more antimicrobial than bovine milk and formula. The Enterococcus faecalis strain, which was not inhibited, produced reutericyclin, which is an analogue of GML and functions as a growth stimulant in bacteria that produce it. Removal of GML and other lipophilic molecules from human milk by ethanol extraction resulted in a loss of antibacterial activity, which was restored by re-addition of GML. GML addition caused bovine milk to become antimicrobial. Human milk but not bovine milk or formula inhibited superantigen and bacterial-induced IL-8 production by model human epithelial cells. GML may contribute beneficially to human milk compared to bovine milk or infant formula.

Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Bacillus subtilis; Cattle; Clostridium perfringens; Enterococcus faecalis; Epithelial Cells; Escherichia coli; Humans; Inflammation; Laurates; Microbial Sensitivity Tests; Milk, Human; Monoglycerides; Staphylococcus aureus; Tenuazonic Acid

Streptococcus mutans is a major pathogen causing human dental caries. As a Gram-positive bacterium with a small genome (about 2 Mb) it is considered a poor source of natural products. Due to a recent explosion in genomic data available for S. mutans strains, we were motivated to explore the natural product production potential of this organism. Bioinformatic characterization of 169 publically available genomes of S. mutans from human dental caries revealed a surprisingly rich source of natural product biosynthetic gene clusters. Anti-SMASH analysis identified one nonribosomal peptide synthetase (NRPS) gene cluster, seven polyketide synthase (PKS) gene clusters and 136 hybrid PKS/NRPS gene clusters. In addition, 211 ribosomally synthesized and post-translationally modified peptides (RiPPs) clusters and 615 bacteriocin precursors were identified by a combined analysis using BAGEL and anti-SMASH. S. mutans harbors a rich and diverse natural product genetic capacity, which underscores the importance of probing the human microbiome and revisiting species that have traditionally been overlooked as "poor" sources of natural products.

Topics: Amino Acid Sequence; Bacteriocins; Biological Products; Biosynthetic Pathways; Data Mining; Genes, Bacterial; Genomics; Humans; Mouth; Multigene Family; Phylogeny; Sequence Alignment; Streptococcus mutans; Tenuazonic Acid

Reutericyclin is a unique antimicrobial tetramic acid produced by some strains of Lactobacillus reuteri. This study aimed to identify the genetic determinants of reutericyclin biosynthesis. Comparisons of the genomes of reutericyclin-producing L. reuteri strains with those of non-reutericyclin-producing strains identified a genomic island of 14 open reading frames (ORFs) including genes coding for a nonribosomal peptide synthetase (NRPS), a polyketide synthase (PKS), homologues of PhlA, PhlB, and PhlC, and putative transport and regulatory proteins. The protein encoded by rtcN is composed of a condensation domain, an adenylation domain likely specific for d-leucine, and a thiolation domain. rtcK codes for a PKS that is composed of a ketosynthase domain, an acyl-carrier protein domain, and a thioesterase domain. The products of rtcA, rtcB, and rtcC are homologous to the diacetylphloroglucinol-biosynthetic proteins PhlABC and may acetylate the tetramic acid moiety produced by RtcN and RtcK, forming reutericyclin. Deletion of rtcN or rtcABC in L. reuteri TMW1.656 abrogated reutericyclin production but did not affect resistance to reutericyclin. Genes coding for transport and regulatory proteins could be deleted only in the reutericyclin-negative L. reuteri strain TMW1.656ΔrtcN, and these deletions eliminated reutericyclin resistance. The genomic analyses suggest that the reutericyclin genomic island was horizontally acquired from an unknown source during a unique event. The combination of PhlABC homologues with both an NRPS and a PKS has also been identified in the lactic acid bacteria Streptococcus mutans and Lactobacillus plantarum, suggesting that the genes in these organisms and those in L. reuteri share an evolutionary origin.

Topics: Anti-Bacterial Agents; Biosynthetic Pathways; DNA, Bacterial; Gene Deletion; Genomic Islands; Lactobacillus plantarum; Limosilactobacillus reuteri; Molecular Sequence Data; Open Reading Frames; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Streptococcus mutans; Tenuazonic Acid

Metronidazole, a mainstay treatment for Clostridium difficile infection (CDI), is often ineffective for severe CDI. Whilst this is thought to arise from suboptimal levels of metronidazole in the colon due to rapid absorption, empirical validation is lacking. In contrast, reutericyclin, an antibacterial tetramic acid from Lactobacillus reuteri, concentrates in the gastrointestinal tract. In this study, we modified metronidazole with reutericyclin's tetramic acid motif to obtain non-absorbed compounds, enabling assessment of the impact of pharmacokinetics on treatment outcomes.. A series of metronidazole-bearing tetramic acid substituents were synthesized and evaluated in terms of anti-C. difficile activities, gastric permeability, in vivo pharmacokinetics, efficacy in the hamster model of CDI and mode of action.. Most compounds were absorbed less than metronidazole in cell-based Caco-2 permeability assays. In hamsters, lead compounds compartmentalized in the colon rather than the bloodstream with negligible levels detected in the blood, in direct contrast with metronidazole, which was rapidly absorbed into the blood and was undetectable in caecum. Accordingly, four leads were more efficacious (P < 0.05) than metronidazole in C. difficile-infected animals. Improved efficacy was not due to an alternative mode of action, as the leads retained the mode of action of metronidazole.. This study provides the clearest empirical evidence that the high absorption of metronidazole lowers treatment outcomes for CDI and suggests a role for the tetramic acid motif for colon-specific drug delivery. This approach also has the potential to lower systemic toxicity and drug interactions of nitroheterocyclic drugs for treating gastrointestine-specific diseases.

Topics: Animals; Anti-Bacterial Agents; Clostridioides difficile; Clostridium Infections; Colon; Disease Models, Animal; Male; Mesocricetus; Metronidazole; Pyrrolidinones; Tenuazonic Acid; Treatment Outcome

The emergence of antimicrobial resistance has created a need for the development of novel antibacterial therapies to treat infection. Natural products that exhibit antibacterial activity offer validated starting points for library generation, and the authors report here that small molecule mimics of tetramate-containing natural products may show antibacterial activity and offer the potential for further optimization.

Topics: Anti-Bacterial Agents; Biological Products; Drug Resistance, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Microbial Sensitivity Tests; Phenotype; Pyrrolidinones; Tenuazonic Acid; Tetrahydronaphthalenes

A range of N-acylpyrrolo[3,4-c]isoxazoles and derived N-acyltetramides has been prepared via a nitrile oxide dipolar cycloaddition approach, as analogues of the acyltetramic acid metabolite reutericyclin, of interest for its antibiotic potential against Gram-positive bacteria including hospital-acquired infections of resistant Clostridium difficile.

Topics: Anti-Bacterial Agents; Clostridioides difficile; Enterocolitis, Pseudomembranous; Humans; Isoxazoles; Lactobacillus; Models, Molecular; Tenuazonic Acid

Whilst the development of membrane-active antibiotics is now an attractive therapeutic concept, progress in this area is disadvantaged by poor knowledge of the structure-activity relationship (SAR) required for optimizing molecules to selectively target bacteria. This prompted us to explore the SAR of the Lactobacillus reuteri membrane-active antibiotic reutericyclin, modifying three key positions about its tetramic acid core. The SAR revealed that lipophilic analogs were generally more active against Gram-positive pathogens, but introduction of polar and charged substituents diminished their activity. This was confirmed by cytometric assays showing that inactive compounds failed to dissipate the membrane potential. Radiolabeled substrate assays indicated that dissipation of the membrane potential by active reutericyclins correlated with inhibition of macromolecular synthesis in cells. However, compounds with good antibacterial activities also showed cytotoxicity against Vero cells and hemolytic activity. Although this study highlights the challenge of optimizing membrane-active antibiotics, it shows that by increasing antibacterial potency the selectivity index could be widened, allowing use of lower non-cytotoxic doses.

Topics: Animals; Anti-Bacterial Agents; Chlorocebus aethiops; Gram-Positive Bacteria; Humans; Limosilactobacillus reuteri; Membranes; Structure-Activity Relationship; Tenuazonic Acid; Vero Cells

The effects of high pressure, temperature, and antimicrobial compounds on endospores of Clostridium spp. were examined. Minimal inhibitory concentrations (MIC) of nisin and reutericyclin were determined for vegetative cells and endospores of Clostridium sporogenes ATCC 7955, Clostridium beijerinckii ATCC 8260, and Clostridium difficile 3195. Endospores of C. sporogenes ATCC 7955 and C. beijerinckii ATCC 8260 were exposed to 90 °C and 90 °C/600 MPa in the presence of 16 mg L(-1) nisin or 6.4 mg L(-1) reutericyclin for 0-60 min in a 0.9% saline solution. Dipicolinic acid (DPA) release was measured using a terbium-DPA fluorescence assay, and endospore permeability was assessed using 4',6-diamidino-2-phenylindole (DAPI) fluorescence. Vegetative cells of C. sporogenes ATCC 7955 exhibited higher sensitivity to nisin relative to endospores, with MIC values 0.23 ± 0.084 mg L(-1) and 1.11 ± 0.48 mg L(-1), respectively. Nisin increased DPA release when endospores were treated at 90 °C; however, only C. sporogenes ATCC 7955 exhibited higher inactivation, suggesting strain or species specific effects. Reutericyclin did not enhance spore inactivation or DPA release. Use of nisin in combination with high pressure, thermal treatments enhanced inactivation of endospores of Clostridium spp. and may have application in foods.

Topics: Anti-Bacterial Agents; Clostridium; Hot Temperature; Microbial Viability; Nisin; Pressure; Spores, Bacterial; Tenuazonic Acid

The stationary phase of Clostridium difficile, which is primarily responsible for diarrhoeal symptoms, is refractory to antibiotic killing. We investigated whether disrupting the functions of the clostridial membrane is an approach to control C. difficile infections by promptly removing growing and non-growing cells.. The bactericidal activities of various membrane-active agents were determined against C. difficile logarithmic-phase and stationary-phase cultures and compared with known antibiotics. Their effects on the synthesis of ATP, toxins A/B and sporulation were also determined. The effect of rodent caecal contents on anti-difficile activities was examined using two reutericyclin lead compounds, clofazimine, daptomycin and other comparator antibiotics.. Most membrane-active agents and partially daptomycin showed concentration-dependent killing of both logarithmic-phase and stationary-phase cultures. The exposure of cells to compounds at their MBC resulted in a rapid loss of viability with concomitant reductions in cellular ATP, toxins A/B and spore numbers. With the exception of nisin, these effects were not due to membrane pore formation. Interestingly, the activity of the proton ionophore nigericin significantly increased as the growth of C. difficile decreased, suggesting the importance of the proton gradient to the survival of non-growing cells. The activities of the lipophilic antimicrobials reutericyclins and clofazimine were reduced by caecal contents.. These findings indicate that C. difficile is uniquely susceptible to killing by molecules affecting its membrane function and bioenergetics, indicating that the clostridial membrane is a novel antimicrobial target for agents to alleviate the burden of C. difficile infections.

Topics: Animals; Anti-Bacterial Agents; Bacterial Load; Cecum; Cell Membrane; Clofazimine; Clostridioides difficile; Clostridium Infections; Cricetinae; Mesocricetus; Microbial Viability; Tenuazonic Acid

This study determined the membrane fluidity of clostridial endospores during treatment with heat and pressure with nisin or reutericyclin. Heating (90°C) reduced laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) general polarization, corresponding to membrane fluidization. Pressure (200 MPa) stabilized membrane order. Reutericyclin and nisin exhibit divergent effects on heat- and pressure-induced spore inactivation and membrane fluidity.

Topics: 2-Naphthylamine; Clostridium; Hot Temperature; Hydrostatic Pressure; Laurates; Membrane Fluidity; Microbial Viability; Nisin; Spores, Bacterial; Tenuazonic Acid

The stationary phase of Clostridium difficile, which is associated with the symptoms of the diarrhoeal disease, is refractory to antibiotic killing. The aim of this study was to explore whether probiotic-derived reutericyclin and related synthetic analogues could kill stationary phase C. difficile at concentrations achievable in the gastrointestinal tract.. The bactericidal activities of reutericyclin and lead compound derivatives were examined against logarithmic and stationary phase cultures of different C. difficile strains. The absorption of compounds across the intestinal epithelia was tested using the Caco-2 permeability model.. Unlike vancomycin and metronidazole, reutericyclins demonstrated concentration-dependent killing, being rapidly bactericidal against both logarithmic and stationary phase cells, at low concentrations (0.09-2 mg/L). The intestinal absorption of unmodified reutericyclin was poor and comparable to that of vancomycin. However, this property varied significantly for the synthetic reutericyclin analogues, ranging from well absorbed to non-absorbed. The non-absorbable compounds were highly effluxed, suggesting this parameter could be modulated to obtain agents with superior efficacy.. Reutericyclins showed excellent potency against the lethal non-growing stage of C. difficile at concentrations that may be attained in the gastrointestinal tract. Since these agents represent novel potential treatments for C. difficile infection, further development of this compound class is warranted.

Topics: Anti-Bacterial Agents; Caco-2 Cells; Clostridioides difficile; Colon; Humans; Microbial Viability; Tenuazonic Acid

The potential for reutericyclin derivatives to be used as topical antibiotics to treat staphylococcal skin infections was investigated. All reutericyclins inhibited the growth of clinical isolates of drug-resistant Staphylococcus aureus. Unlike the standard topical agent mupirocin, most reutericyclin derivatives eradicated staphylococcal biofilms. Moreover, two compounds formulated in hydrophilic petrolatum (10%, wt/wt) were efficacious in treating S. aureus superficial skin infections in mice. These data exemplify the prospect of developing reutericyclins as new topical antibiotics.

Topics: Animals; Anti-Bacterial Agents; Biofilms; Cell Line; Fibroblasts; Humans; Male; Mice; Pyrrolidinones; Staphylococcal Skin Infections; Tenuazonic Acid

The effect of environmental conditions on the production of homo-polysaccharides and oligosaccharides from sucrose and the regulation of glycosyltransferase genes responsible for biosynthesis of homo-polysaccharides was determined in Lactobacillus reuteri TMW1.106 (reutericyclin-producer) and LTH5448 (reutericyclin-negative). Strain L. reuteri TMW 1.106 harbours the glycosyltransferase genes gtfA and inu, strain LTH5448 harbours a fructosyltransferase, ftfA. Fructan and fructose-oligosaccharide (FOS) production in both strains was inducible by reutericyclin, trans-isohumulone, and nigericin at the levels of their minimum inhibitory concentrations (MIC) as well as phenylethanol (6mM) and elevated growth temperatures (45 degrees C), but not by nisin, CCCP or gramicidin. Elevated temperature (45 degrees C), reutericyclin or trans-isohumulone but not CCCP furthermore increased enhanced inu and ftfA transcription in L. reuteri TMW1.106 and LTH5448, respectively. Generally, effects of the various agents on fructosyltransferase transcription corresponded to their effect on formation of poly and oligosaccharides from sucrose. The effect of membrane-active agents on fructosyltransferase expression was compared to their effect on membrane biophysical parameters. The ability of chemical and physical agents to induce expression of fructosyltransferases correlated to their effect on the membrane lateral pressure as measured by pyrene-labelled phospholipids in membrane vesicles. Dextran, levan and fructose-oligosaccharides added at 50gL(-1) protected L. reuteri towards the membrane-active inhibitors nisin, reutericyclin, and CCCP. The induction of glycosyltransferases by membrane stress indicates a protective role of fructans and FOS to lactobacilli exposed to physical and chemical environmental stressors.

Topics: Cyclopentanes; Fructans; Hexosyltransferases; Ionophores; Limosilactobacillus reuteri; Nigericin; Oligosaccharides; Temperature; Tenuazonic Acid

Reutericyclin is a small molecular weight antibiotic produced by the sourdough isolate Lactobacillus reuteri LTH2584. This strain was isolated from an industrial sourdough, SER, in 1988. To determine whether reutericyclin formation contributes to the stable persistence of L. reuteri in sourdough, evaluations were made on whether reutericyclin-producing strains were among L. reuteri isolates from the SER sourdough obtained in 1994 and 1998. These strains were characterised on species and strain level by physiological tests and randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) patterns. Reutericyclin production in dough was evaluated by two methods, a bioassay and HPLC. Throughout 10 years of continuous propagation, reutericyclin-producing L. reuteri strains were present in SER sourdough. All isolates exhibited similar physiological properties and molecular typing revealed closely related patterns. Two isolates obtained in 1994 and 1998 were identical. Reutericyclin produced in situ by L. reuteri was active in dough against reutericyclin-sensitive L. sanfranciscensis. The reutericyclin concentration in dough fermented with L. reuteri was 5 mg kg(-1). The results indicate that reutericyclin production contributed to the stable persistence of L. reuteri in sourdough. Because reutericyclin is produced in active concentrations during sourdough fermentations, it is a suitable candidate for use as natural preservative.

Topics: Anti-Bacterial Agents; Bread; Chromatography, High Pressure Liquid; DNA, Bacterial; Fermentation; Food Microbiology; Lactobacillus; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Tenuazonic Acid

The mode of action of reutericyclin was determined with fluorescent dyes that probed the permeability of the cytoplasmic membrane by large molecules, protons, and potassium. A comparison of reutericyclin activity with those of nisin, nigericin, and valinomycin demonstrated that reutericyclin does not form pores but selectively dissipates the transmembrane proton potential.

Topics: Anti-Bacterial Agents; Cell Membrane; Cell Membrane Permeability; Fluorescent Dyes; Lactobacillus; Membrane Potentials; Microbial Sensitivity Tests; Nigericin; Nisin; Potassium; Tenuazonic Acid; Valinomycin

Lactobacillus reuteri LTH2584 exhibits antimicrobial activity that can be attributed neither to bacteriocins nor to the production of reuterin or organic acids. We have purified the active compound, named reutericyclin, to homogeneity and characterized its antimicrobial activity. Reutericyclin exhibited a broad inhibitory spectrum including Lactobacillus spp., Bacillus subtilis, B. cereus, Enterococcus faecalis, Staphylococcus aureus, and Listeria innocua. It did not affect the growth of gram-negative bacteria; however, the growth of lipopolysaccharide mutant strains of Escherichia coli was inhibited. Reutericyclin exhibited a bactericidal mode of action against Lactobacillus sanfranciscensis, Staphylococcus aureus, and B. subtilis and triggered the lysis of cells of L. sanfranciscensis in a dose-dependent manner. Germination of spores of B. subtilis was inhibited, but the spores remained unaffected under conditions that do not permit germination. The fatty acid supply of the growth media had a strong effect on reutericyclin production and its distribution between producer cells and the culture supernatant. Reutericyclin was purified from cell extracts and culture supernatant of L. reuteri LTH2584 cultures grown in mMRS by solvent extraction, gel filtration, RP-C(8) chromatography, and anion-exchange chromatography, followed by rechromatography by reversed-phase high-pressure liquid chromatography. Reutericyclin was characterized as a negatively charged, highly hydrophobic molecule with a molecular mass of 349 Da. Structural characterization (A. Höltzel, M. G. Gänzle, G. J. Nicholson, W. P. Hammes, and G. Jung, Angew. Chem. Int. Ed. 39:2766-2768, 2000) revealed that reutericyclin is a novel tetramic acid derivative. The inhibitory activity of culture supernatant of L. reuteri LTH2584 corresponded to that of purified as well as synthetic reutericyclin.

Topics: Anti-Bacterial Agents; Bacillus subtilis; Emulsions; Escherichia coli; Fatty Acids; Gram-Negative Bacteria; Gram-Positive Bacteria; Kinetics; Lactobacillus; Lipopolysaccharides; Microbial Sensitivity Tests; Staphylococcus aureus; Tenuazonic Acid