Domain redistribution within ergosterol-containing model membranes in the presence of the antimicrobial compound fengycin

The cyclic lipopeptide fengycin, produced by Bacillus subtilis, exhibits its antimicrobial capabilities by altering the integrity of the cell membrane of plant pathogens. Previous work has correlated fengycin activity with membrane characteristics, such as sterol content. This work focused on the influence of fengycin on supported lipid bilayers containing varying levels of ergosterol. Total internal reflection fluorescence (TIRF) microscopy was used to visualize and distinguish ordered (L_β/L_o) and disordered (L_α/L_d) domains in the model membranes following exposure to low (50 μg) and high (500 μg) fengycin doses. Application of an initial low dose of fengycin to 0% and 3% ergosterol-containing bilayers resulted in redistribution of L_α/L_β and L_o/L_d domains, respectively, which the bilayers compensated and corrected for over time. These membranes were unable to tolerate a second 50 μg dose or a single high fengycin dose. The 6% ergosterol bilayers were able to tolerate sequential low doses of fengycin. Exposure of these bilayers to the high fengycin dose caused a decrease in the number of L_o domains, albeit less than that seen in the 0% and 3% ergosterol bilayers. Bilayers containing 12% ergosterol, exhibited the least amount of change after fengycin exposure. These were the only bilayer to exhibit an increase in area taken up by ordered domains. These results suggest fengycin may preferentially act on the L_β or L_o phase, the area in which ergosterol resides. Bilayers containing low levels of ergosterol appear to be more sensitive to the lipopeptide, suggesting ergosterol plays a role in buffering perturbations caused by fengycin.     

Effects of fengycin from Bacillus subtilis fmbJ on apoptosis and necrosis in Rhizopus stolonifer

The lipopeptide antibiotic fengycin, produced by Bacillus subtilis, strongly inhibits growth of filamentous fungi. In this study, we evaluated the effects of fengycin treatment on apoptosis and necrosis in Rhizopus stolonifer by means of cell staining and epifluorescence microscopy. At fengycin concentrations less than 50 μg/ml, treated fungal cells demonstrated a dose-dependent increase in apoptosis-associated markers compared with the untreated control. These markers included chromatin condensation, reactive oxygen species accumulation, mitochondrial membrane potential depolarization, phosphatidylserine externalization, and the occurrence of DNA strand breaks. These results showed that fungal cells were impaired in a number of important functions and entered apoptosis upon treatment with low concentrations of fengycin. In contrast, high concentrations (>50 μg/ml) induced necrosis, indicating that the fungicidal action of fengycin operates via two modes: apoptosis at low concentrations and necrosis at high concentrations. Additionally, the apoptotic effect that we have shown suggests that lower concentrations of fengycin than previously thought may be effective for food preservation.     

Cyclic lipopeptide profile of three <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strains; antagonists of <Emphasis Type="Italic">Fusarium</Emphasis> head blight

The objective of the study was to identify the lipopetides associated with three Bacillus subtilis strains. The strains are antagonists of Gibberella zeae, and have been shown to be effective in reducing Fusarium head blight in wheat. The lipopeptide profile of three B. subtilis strains (AS43.3, AS43.4, and OH131.1) was determined using mass spectroscopy. Strains AS43.3 and AS43.4 produced the anti-fungal lipopeptides from the iturin and fengycin family during the stationary growth phase. All three strains produced the lipopeptide surfactin at different growth times. Strain OH131.1 only produced surfactin under these conditions. The antifungal activity of the culture supernatant and individual lipopeptides was determined by the inhibition of G. zeae. Cell-free supernatant from strains AS43.3 and AS43.4 demonstrated strong antibiosis of G. zeae, while strain OH131.1 had no antibiosis activity. These results suggest a different mechanism of antagonism for strain OH131.1, relative to AS43.3 and AS43.4.     

Interactions between Fengycin and Model Bilayers Quantified by Coarse-Grained Molecular Dynamics

Bacteria, particularly of the genus Bacillus, produce a wide variety of antifungal compounds. They act by affecting the lipid bilayers of fungal membranes, causing curvature-induced strain and eventual permeabilization. One class of these, known as fengycins, has been commercialized for treating agricultural infections and shows some promise as a possible antifungal pharmaceutical. Understanding the mechanism by which fengycins damage lipid bilayers could prove useful to the future development of related antifungal treatments. In this work, we present multi-microsecond-long simulations of fengycin interacting with different lipid bilayer systems. We see fengycin aggregation and uncover a clear aggregation pattern that is partially influenced by bilayer composition. We also quantify some local bilayer perturbations caused by fengycin binding, including curvature of the lipid bilayer and local electrostatic-driven reorganization.     

Interactions between Fengycin and Model Bilayers Quantified by Coarse-Grained Molecular Dynamics

Bacteria, particularly of the genus Bacillus, produce a wide variety of antifungal compounds. They act by affecting the lipid bilayers of fungal membranes, causing curvature-induced strain and eventual permeabilization. One class of these, known as fengycins, has been commercialized for treating agricultural infections and shows some promise as a possible antifungal pharmaceutical. Understanding the mechanism by which fengycins damage lipid bilayers could prove useful to the future development of related antifungal treatments. In this work, we present multi-microsecond-long simulations of fengycin interacting with different lipid bilayer systems. We see fengycin aggregation and uncover a clear aggregation pattern that is partially influenced by bilayer composition. We also quantify some local bilayer perturbations caused by fengycin binding, including curvature of the lipid bilayer and local electrostatic-driven reorganization.     

Production of surfactin and fengycin by Bacillus subtilis in a bubbleless membrane bioreactor

Surfactin and fengycin are lipopeptide biosurfactants produced by Bacillus subtilis. This work describes for the first time the use of bubbleless bioreactors for the production of these lipopeptides by B. subtilis ATCC 21332 with aeration by a hollow fiber membrane air–liquid contactor to prevent foam formation. Three different configurations were tested: external aeration module made from either polyethersulfone (reactor BB1) or polypropylene (reactor BB2) and a submerged module in polypropylene (reactor BB3). Bacterial growth, glucose consumption, lipopeptide production, and oxygen uptake rate were monitored during the culture in the bioreactors. For all the tested membranes, the bioreactors were of satisfactory bacterial growth and lipopeptide production. In the three configurations, surfactin production related to the culture volume was in the same range: 242, 230, and 188 mg l⁻¹ for BB1, BB2, and BB3, respectively. Interestingly, high differences were observed for fengycin production: 47 mg l⁻¹ for BB1, 207 mg l⁻¹ for BB2, and 393 mg l⁻¹ for BB3. A significant proportion of surfactin was adsorbed on the membranes and reduced the volumetric oxygen mass transfer coefficient. The degree of adsorption depended on both the material and the structure of the membrane and was higher with the submerged polypropylene membrane.     

Effects of cholesterol on the mechanism of fengycin,a biofungicide

Fengycins are a class of antifungal lipopeptides synthesized by the bacteria Bacillus subtilis, commercially available as the primary component of the agricultural fungicide Serenade. They are toxic to fungi but far less to mammalian cells. One key difference between mammalian and fungal cell membranes is the presence of cholesterol only in the former; recent experimental work showed that the presence of cholesterol reduces fengycin-induced membrane leakage. Since our previous all-atom and coarse-grained simulations suggested that aggregation of membrane-bound fengycin is central to its ability to disrupt membranes, we hypothesized that cholesterol might reduce fengycin aggregation. Here, we test this hypothesis using coarse-grained molecular dynamics simulations, with sampling enhanced via the weighted ensemble method. The results indicate that cholesterol subtly alters the size distribution for fengycin aggregates, limits the lateral range of their membrane disordering, and reduces the ability of aggregates to bend the membrane. Taken together, these phenomena may account for cholesterol’s effects on fengycin activity.     

Antimicrobial activity and membrane selective interactions of a synthetic lipopeptide MSI-843

Lipopeptide MSI-843 consisting of the nonstandard amino acid ornithine (Oct-OOLLOOLOOL-NH₂) was designed with an objective towards generating non-lytic short antimicrobial peptides, which can have significant pharmaceutical applications. Octanoic acid was coupled to the N-terminus of the peptide to increase the overall hydrophobicity of the peptide. MSI-843 shows activity against bacteria and fungi at micromolar concentrations. It permeabilizes the outer membrane of Gram-negative bacterium and a model membrane mimicking bacterial inner membrane. Circular dichroism investigations demonstrate that the peptide adopts α-helical conformation upon binding to lipid membranes. Isothermal titration calorimetry studies suggest that the peptide binding to membranes results in exothermic heat of reaction, which arises from helix formation and membrane insertion of the peptide. ²H NMR of deuterated-POPC multilamellar vesicles shows the peptide-induced disorder in the hydrophobic core of bilayers. ³¹P NMR data indicate changes in the lipid head group orientation of POPC, POPG and Escherichia colitotal lipid bilayers upon peptide binding. Results from ³¹P NMR and dye leakage experiments suggest that the peptide selectively interacts with anionic bilayers at low concentrations (up to 5 mol%). Differential scanning calorimetry experiments on DiPOPE bilayers and ³¹P NMR data from E.coli total lipid multilamellar vesicles indicate that MSI-843 increases the fluid lamellar to inverted hexagonal phase transition temperature of bilayers by inducing positive curvature strain. Combination of all these data suggests the formation of a lipid-peptide complex resulting in a transient pore as a plausible mechanism for the membrane permeabilization and antimicrobial activity of the lipopeptide MSI-843.     

Identification and biochemical characteristics of lipopeptides from Bacillus mojavensis A21

This study reports the potential of a marine bacterium, Bacillus mojavensis A21, to produce lipopeptide biosurfactants. The crude lipopeptide mixture was found to be very effective in reducing surface tension to 31 mN m⁻¹. PCR experiments using degenerate primers revealed the presence of nonribosomal peptide synthetases genes implied in the biosyntheses of fengycin and surfactin. Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) performed on whole cells of B. mojavensis A21 confirmed the presence of lipopeptides identified as members of surfactin and fengycin families. Further, a detailed analysis performed by MALDI-TOF-TOF revealed the presence of pumilacidin compounds. The crude lipopeptide mixture was tested for its inhibitory activity against Gram-positive and Gram-negative bacteria, and fungal strains. It was found to display significant antimicrobial activity. Strain A21 lipopeptide mixture was insensitive to proteolytic enzymes, stable between pH 3.0 and 11.0, and resistant to high temperature. Production of lipopeptides is a characteristic of several Bacillus species, but to our knowledge this is the first report involving identification of pumilacidin, surfactin and fengycin isoforms in a B. mojavensis strain.     

Antibacterial peptide pleurocidin forms ion channels in planar lipid bilayers

Pleurocidin, a 25-residue α helical cationic peptide, isolated from skin mucous secretions of the winter flounder, displays a strong anti-microbial activity and appears to play a role in innate host defence. This peptide would be responsible for pore formation in the membrane of bacteria leading to lysis and therefore death. In this study, we investigated the behaviour of pleurocidin in different planar lipid bilayers to determine its mechanism of membrane permeabilisation. Macroscopic conductance experiments showed that pleurocidin did not display a pore-forming activity in neutral phosphatidylcholine/phosphatidylethanolamine (PC/PE) lipid bilayers. However, in 7:3:1 PC/PE/phosphatidylserine (PS) lipid bilayers, pleurocidin showed reproducible I/V curves at different peptide concentrations. This activity is confirmed by single-channel experiments since well-defined ion channels were obtained if the lipid mixture was containing an anionic lipid (PS). The ion channel characteristics such as—no voltage dependence, only one unitary conductance, linear relation ship current-voltage—, are not in favour of the membrane permeabilisation according to the barrel model but rather by the toroidal pore formation.     

Antimicrobial Protegrin-1 Forms Ion Channels: Molecular Dynamic Simulation, Atomic Force Microscopy, and Electrical Conductance Studies

Antimicrobial peptides (AMPs) are an emerging class of antibiotics for controlling health effects of antibiotic-resistant microbial strains. Protegrin-1 (PG-1) is a model antibiotic among β-sheet AMPs. Antibiotic activity of AMPs involves cell membrane damage, yet their membrane interactions, their 3D membrane-associated structures and the mechanism underlying their ability to disrupt cell membrane are poorly understood. Using complementary approaches, including molecular dynamics simulations, atomic force microscopy (AFM) imaging, and planar lipid bilayer reconstitution, we provide computational and experimental evidence that PG-1, a β-hairpin peptide, forms ion channels. Simulations indicate that PG-1 forms channel-like structures with loosely attached subunits when reconstituted in anionic lipid bilayers. AFM images show the presence of channel-like structures when PG-1 is reconstituted in dioleoylphosphatidylserine/palmitoyloleoyl phosphatidylethanolamine bilayers or added to preformed bilayers. Planar lipid bilayer electrical recordings show multiple single channel conductances that are consistent with the heterogeneous oligomeric channel structures seen in AFM images. PG-1 channel formation seems to be lipid-dependent: PG-1 does not easily show ion channel electrical activity in phosphatidylcholine membranes, but readily shows channel activity in membranes rich in phosphatidylethanolamine or phosphatidylserine. The combined results support a model wherein the β-hairpin PG-1 peptide acts as an antibiotic by altering cell ionic homeostasis through ion channel formation in cell membranes.     

Real-time quantitative analysis of lipid disordering by aurein 1.2 during membrane adsorption, destabilisation and lysis

Effective antimicrobial peptides (AMPs) distinguish between the host and microbial cells, show selective antimicrobial activity and exhibit a fast killing mechanism. Although understanding the structure-function characteristics of AMPs is important, the impact of the peptides on the architecture of membranes with different lipid compositions is also critical in understanding the molecular mechanism and specificity of membrane destabilisation. In this study, the destabilisation of supported lipid bilayers (SLBs) by the AMP aurein 1.2 was quantitatively analysed by dual polarisation interferometry. The lipid bilayers were formed on a planar silicon oxynitride chip, and composed of mixed synthetic lipids, or Escherichiacoli lipid extract. The molecular events leading sequentially from peptide adsorption to membrane lysis were examined in real time by changes in bilayer birefringence (lipid molecular ordering) as a function of membrane-bound peptide mass. Aurein 1.2 bound weakly without any change in membrane ordering at low peptide concentration (5 μM), indicating a surface-associated state without significant perturbation in membrane structure. At 10 μM peptide, marked reversible changes in molecular ordering were observed for all membranes except DMPE/DMPG. However, at 20 μM aurein 1.2, removal of lipid molecules, as determined by mass loss with a concomitant decrease in birefringence during the association phase, was observed for DMPC and DMPC/DMPG SLBs, which indicates membrane lysis by aurein. The membrane destabilisation induced by aurein 1.2 showed cooperativity at a particular peptide/lipid ratio with a critical mass/molecular ordering value. Furthermore, the extent of membrane lysis for DMPC/DMPG was nearly double that for DMPC. However, no lysis was observed for DMPC/DMPG/cholesterol, DMPE/DMPG and E. coli SLBs. The extent of birefringence changes with peptide mass suggested that aurein 1.2 binds to the membrane without inserting through the bilayer and membrane lysis occurs through detergent-like micellisation above a critical P/L ratio. Real-time quantitative analysis of the structural properties of membrane organisation has allowed the membrane destabilisation process to be resolved into multiple steps and provides comprehensive information to determine the molecular mechanism of aurein 1.2 action.     

Vesicle Leakage Reflects the Target Selectivity of Antimicrobial Lipopeptides from Bacillus subtilis

Cyclic lipopeptides act against a variety of plant pathogens and are thus highly efficient crop-protection agents. Some pesticides contain Bacillus subtilis strains that produce lipopeptide families, such as surfactins (SF), iturins (IT), and fengycins (FE). The antimicrobial activity of these peptides is mainly mediated by permeabilizing cellular membranes. We used a fluorescence-lifetime based leakage assay to examine the effect of individual lipid components in model membranes on lipopeptide activity. Leakage induction by FE was strongly inhibited by cholesterol (CHOL) as well as by phosphatidylethanolamine (PE) and -glycerol (PG) lipids. Already moderate amounts of CHOL increased the tolerable FE content in membranes by an order of magnitude to 0.5 FE per PC + CHOL. This indicates reduced FE-lipid demixing and aggregation, which is known to be required for membrane permeabilization and explains the strong inhibition by CHOL. Ergosterol (ERG) had a weak antagonistic effect. This confirms results of microbiological tests and agrees with the fungicidal activity and selectivity of FE. SF is known to be much less selective in its antimicrobial action. In line with this, liposome leakage by SF was little affected by sterols and PE. Interestingly, PG increased SF activity and changed its leakage mechanism toward all-or-none, suggesting more specific, larger, and/or longer-lived defect structures. This may be because of the reduced energetic cost of locally accumulating anionic SF in an anionic lipid matrix. IT was found largely inactive in our assays. B. subtilis QST713 produces the lipopeptides in a ratio of 6 mol SF: 37 mol FE: 57 mol IT. Leakage induced by this native mixture was inhibited by CHOL and PE, but unaffected by ERG and by PG in the absence of PE. Note that fungi contain anionic lipids, but little PE. Hence, our data explain the strong, fungicidal activity and selectivity of B. subtilis QST713 lipopeptides.     

The antagonistic strain Bacillus subtilis UMAF6639 also confers protection to melon plants against cucurbit powdery mildew by activation of jasmonate-and salicylic acid-dependent defence responses

Biological control of plant diseases has gained acceptance in recent years. Bacillus subtilis UMAF6639 is an antagonistic strain specifically selected for the efficient control of the cucurbit powdery mildew fungus Podosphaera fusca, which is a major threat to cucurbits worldwide. The antagonistic activity relies on the production of the antifungal compounds iturin and fengycin. In a previous study, we found that UMAF6639 was able to induce systemic resistance (ISR) in melon and provide additional protection against powdery mildew. In the present work, we further investigated in detail this second mechanism of biocontrol by UMAF6639. First, we examined the signalling pathways elicited by UMAF6639 in melon plants, as well as the defence mechanisms activated in response to P. fusca. Second, we analysed the role of the lipopeptides produced by UMAF6639 as potential determinants for ISR activation. Our results demonstrated that UMAF6639 confers protection against cucurbit powdery mildew by activation of jasmonate- and salicylic acid-dependent defence responses, which include the production of reactive oxygen species and cell wall reinforcement. We also showed that surfactin lipopeptide is a major determinant for stimulation of the immune response. These results reinforce the biotechnological potential of UMAF6639 as a biological control agent.     

Structural and functional characterization of gene clusters directing nonribosomal synthesis of bioactive cyclic lipopeptides in Bacillus amyloliquefaciens strain FZB42

The environmental strain Bacillus amyloliquefaciens FZB42 promotes plant growth and suppresses plant pathogenic organisms present in the rhizosphere. We sampled sequenced the genome of FZB42 and identified 2,947 genes with >50% identity on the amino acid level to the corresponding genes of Bacillus subtilis 168. Six large gene clusters encoding nonribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) occupied 7.5% of the whole genome. Two of the PKS and one of the NRPS encoding gene clusters were unique insertions in the FZB42 genome and are not present in B. subtilis 168. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis revealed expression of the antibiotic lipopeptide products surfactin, fengycin, and bacillomycin D. The fengycin (fen) and the surfactin (srf) operons were organized and located as in B. subtilis 168. A large 37.2-kb antibiotic DNA island containing the bmy gene cluster was attributed to the biosynthesis of bacillomycin D. The bmy island was found inserted close to the fen operon. The responsibility of the bmy, fen, and srf gene clusters for the production of the corresponding secondary metabolites was demonstrated by cassette mutagenesis, which led to the loss of the ability to produce these peptides. Although these single mutants still largely retained their ability to control fungal spread, a double mutant lacking both bacillomycin D and fengycin was heavily impaired in its ability to inhibit growth of phytopathogenic fungi, suggesting that both lipopeptides act in a synergistic manner.     

Anionic Lipids Modulate the Activity of the Aquaglyceroporin GlpF

The structure and composition of a biological membrane can severely influence the activity of membrane-embedded proteins. Here, we show that the E. coli aquaglyceroporin GlpF has only little activity in lipid bilayers formed from native E. coli lipids. Thus, at first glance, GlpF appears to not be optimized for its natural membrane environment. In fact, we found that GlpF activity was severely affected by negatively charged lipids regardless of the exact chemical nature of the lipid headgroup, whereas GlpF was not sensitive to changes in the lateral membrane pressure. These observations illustrate a potential mechanism by which the activity of an α-helical membrane protein is modulated by the negative charge density around the protein.     

γ-Hemolysin oligomeric structure and effect of its formation on supported lipid bilayers: An AFM Investigation

γ-Hemolysins are bicomponent β-barrel pore forming toxins produced by Staphylococcus aureus as water-soluble monomers, which assemble into oligomeric pores on the surface of lipid bilayers. Here, after investigating the oligomeric structure of γ-hemolysins on supported lipid bilayers (SLBs) by atomic force microscopy (AFM), we studied the effect produced by this toxin on the structure of SLBs. We found that oligomeric structures with different number of monomers can assemble on the lipid bilayer being the octameric form the stablest one. Moreover, in this membrane model we found that γ-hemolysins can form clusters of oligomers inducing a curvature in the lipid bilayer, which could probably enhance the aggressiveness of these toxins at high concentrations.     

Induction of apoptosis in human cancer cells by a Bacillus lipopeptide bacillomycin D

A newly isolated and characterized Bacillus amyloliquefaciens strain fiply 3A has been found to produce an extracellular cyclic lipopeptide which structurally resembled bacillomycin D, earlier reported to be produced by Bacillus subtilis. The lipopeptide showed a dose dependent killing of three different human cancer cell lines viz. A549 (alveolar adenocarcinoma), A498 (renal carcinoma) and HCT-15 (colon adenocarcinoma), while not affecting the normal cell line L-132 (pulmonary epithelial cells) when analyzed using MTT assay and FACS analysis. Staining the cells with H₂-DCFDA showed an increase in reactive oxygen species (ROS) formation in the lipopeptide treated cell population. Hoechst 33342 staining of nuclei further indicated apoptosis as a major mechanism of cell death in lipopeptide treated cells and the typical symptoms of apoptosis including cell shrinkage, nuclear condensation and fragmentation of nuclei were observed. Lipopeptide treatment induced extensive DNA damage in the treated cells, which was indicated by a TUNEL assay. Flow cytometric analysis exhibited lipopeptide concentration dependent apoptosis which was further confirmed during clonogenic assay of the lipopeptide treated cells.     

Lipid-mediated regulation of pore-forming activity of syringomycin E by thyroid hormones and xanthene dyes

The effects of dipole modifiers, thyroid hormones (thyroxine and triiodothyronine) and xanthene dyes (Rose Bengal, phloxineB, erythrosin, eosinY and fluorescein) on the pore-forming activity of the lipopeptide syringomycin E (SRE) produced by Pseudomonas syringae were studied in a model bilayer. Thyroxine does not noticeably influence the steady-state number of open SRE channels (N_op), whereas triiodothyronine decreases it 10-fold at − 50 mV. Rose Bengal, phloxine B and erythrosin significantly increase N_op by 350, 100 and 70 times, respectively. Eosin Y and fluorescein do not practically affect the pore-forming activity of SRE. Recently, we showed that hormones decrease the dipole potential of lipid bilayers by approximately 60 mV at 50 μM, while Rose Bengal, phloxine B and erythrosin at 2.5 μM reduce the membrane dipole potential by 120, 80 and 50 mV, respectively. In the present study using differential scanning microcalorimetry, confocal fluorescence microscopy, the calcein release technique and measurements of membrane curvature elasticity, we show that triiodothyronine strongly affects the fluidity of model membranes: its addition leads to a significant decrease in the temperature and cooperativity of the main phase transition of DPPC, calcein leakage from DOPC vesicles, fluidization of solid domains in DOPC/DPPC liposomes, and promotion of lipid curvature stress. Thyroxine exerts a weaker effect. Xanthene dyes do not influence the phase transition of DPPC. Despite the decrease in the dipole potential, thyroid hormones modulate SRE channels predominantly via the elastic properties of the membrane, whereas the xanthene dyes Rose Bengal, phloxine B and erythrosine affect SRE channels via bilayer electrostatics.     

Lipopeptide surfactants: Production,recovery and pore forming capacity

Lipopeptides are microbial surface active compounds produced by a wide variety of bacteria, fungi and yeast. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Surfactin, iturin and fengycin of Bacillus subtilis are among the most studied lipopeptides. This review will present the main factors encountering lipopeptides production along with the techniques developed for their extraction and purification. Moreover, we will discuss their ability to form pores and destabilize biological membrane permitting their use as antimicrobial, hemolytic and antitumor agents. These open great potential applications in biomediacal, pharmaceutic and agriculture fields.