Search Results (438)

This study investigated white wastewater (WW) as a potential source of antimicrobial peptides, employing hydrolysis with Pronase E followed by separation through electrodialysis with ultrafiltration membranes (EDUF) to increase the value of dairy components within a circular economy framework. The WW hydrolysate was divided into two key fractions: the cationic recovery compartment (CRC) and the anionic recovery compartment (ARC). The EDUF process effectively separated peptides, with peptide migration rates reaching 6.83 ± 0.59 g/m²·h for CRC and 6.19 ± 0.66 g/m²·h for ARC. Furthermore, relative energy consumption (REC) increased from 1.15 Wh/g to 2.05 Wh/g over three hours, in line with trends observed in recent studies on electrodialysis energy use. Although 29 peptides were statistically selected from the CRC (20) and ARC (9) compartments, no antibacterial activity was exhibited against Clostridium tyrobutyricum and Pseudomonas aeruginosa; however, antifungal activity was observed in the feed and ARC compartments. Peptides from the ARC demonstrated activity against Mucor racemosus (MIC = 0.156 mg/mL) and showed selective antifungal effects against Penicillium commune (MIC = 0.156 mg/mL). This innovative approach paves the way for improving the recovery of anionic peptides through further optimization of the EDUF process. Future perspectives include synthesizing selected peptides and evaluating their antifungal efficacy against these and other microbial strains, offering exciting potential for applications in food preservation and beyond. Full article

TasA gene, encoding a functional amyloid protein critical for biofilm formation and antimicrobial activity, was cloned from the endophytic strain Bacillus amyloliquefaciens BS-3, isolated from rubber tree roots. This study identified the shortest functional TasA variant (483 bp, 160 aa) reported to date, featuring unique amino acid substitutions in conserved domains. Bioinformatics analysis predicted a signal peptide (1–27 aa) and transmembrane domain (7–29 aa), which were truncated to optimize heterologous expression. Two prokaryotic vectors (pET28a and pCZN1) were constructed, with pCZN1-TasA expressed solubly in Escherichia coli Arctic Express at 15 °C, while pET28a-TasA formed inclusion bodies at 37 °C. Purified recombinant TasA exhibited potent antifungal activity, achieving 98.6% ± 1.09 inhibition against Colletotrichum acutatum, 64.77% ± 1.34 against Alternaria heveae. Notably, TasA completely suppressed spore germination in C. acutatum and Oidium heveae Steinmannat 60 μg/mL. Structural analysis via AlphaFold3 revealed that truncation enhanced protein stability. These findings highlight BS-3-derived TasA as a promising biocontrol agent, providing molecular insights for developing protein-based biopesticides against rubber tree pathogens. Full article

The worldwide increase in antifungal resistance, particularly in Candida sp., requires the exploration of novel therapeutic agents. Natural compounds have been a rich source of antimicrobial molecules, where peptides constitute the class of the most bioactive components. Therefore, this study looks into the target-specific binding efficacy of insect-derived antifungal peptides (n = 37) as possible alternatives to traditional antifungal treatments. Using computational methods, namely the HPEPDOCK and HDOCK platforms, molecular docking was performed to evaluate the interactions between selected key fungal targets, lanosterol 14-demethylase, or LDM (PDB ID: 5V5Z), secreted aspartic proteinase-5, or Sap-5 (PDB ID: 2QZX), N-myristoyl transferase, or NMT (PDB ID: 1NMT), and dihydrofolate reductase, or DHFR, of C. albicans. The three-dimensional peptide structure was modelled through the PEP-FOLD 3.5 tool. Further, we predicted the physicochemical properties of these peptides through the ProtParam and PEPTIDE 2.0 tools to assess their drug-likeness and potential for therapeutic applications. In silico results show that Blap-6 from Blaps rhynchopeter and Gomesin from Acanthoscurria gomesiana have the most antifungal potential against all four targeted proteins in Candida sp. Additionally, a molecular dynamics simulation study of LDM-Blap-6 was carried out at 100 nanoseconds. The overall predictions showed that both have strong binding abilities and are good candidates for drug development. In in vitro studies, Gomesin achieved complete biofilm eradication in three out of four Candida species, while Blap-6 showed moderate but consistent reduction across all species. C. tropicalis demonstrated relative resistance to complete eradication by both peptides. The present study provides evidence to support the antifungal activity of certain insect peptides, with potential to be used as alternative drugs or as a template for a new synthetic or modified peptide in pursuit of effective therapies against Candida spp. Full article

In the context of the valorization of agri-food by-products, tomato (Solanum lycopersicum L.) seeds represent a protein-rich matrix containing potential bioactives. The aim of the present work is to develop a biochemical pipeline for (i) achieving high protein recovery from tomato seed, (ii) optimizing the hydrolysis with different proteases, and (iii) characterizing the resulting peptides. This approach was instrumental for obtaining and selecting the most promising peptide mixture to test for antifungal activity. To this purpose, proteins from an alkaline extraction were treated with bromelain, papain, and pancreatin, and the resulting hydrolysates were assessed for their protein/peptide profiles via SDS-PAGE, SEC-HPLC, and RP-HPLC. Bromelain hydrolysate was selected for antifungal tests due to its greater quantity of peptides, in a broader spectrum of molecular weights and polarity/hydrophobicity profiles, and higher DPPH radical scavenging activity, although all hydrolysates exhibited antioxidant properties. In vitro assays demonstrated that the bromelain-digested proteins inhibited the growth of Fusarium graminearum and F. oxysporum f.sp. lycopersici in a dose-dependent manner, with a greater effect at a concentration of 0.1 mg/mL. The findings highlight that the enzymatic hydrolysis of tomato seed protein represents a promising strategy for converting food by-products into bioactive agents with agronomic applications, supporting sustainable biotechnology and circular economy strategies. Full article

Burkholderia gladioli is a multifaceted bacterium with both pathogenic and beneficial strains, and nonpathogenic Burkholderia species have shown potential as plant growth-promoting rhizobacteria (PGPRs) and biocontrol agents. However, the molecular mechanisms underlying their beneficial functions remain poorly characterized. This study systematically investigated the antimicrobial mechanisms and plant growth-promoting properties of B. gladioli strain ZBSF BH07, isolated from the grape rhizosphere, by combining genomic and functional analyses, including whole-genome sequencing, gene annotation, phylogenetic and comparative genomics, in vitro antifungal assays, and plant growth promotion evaluations. The results showed that ZBSF BH07 exhibited broad-spectrum antifungal activity, inhibiting 14 grape pathogens with an average inhibition rate of 56.58% and showing dual preventive/curative effects against grape white rot, while also significantly promoting grape seedling growth with increases of 54.9% in plant height, 172.9% in root fresh weight, and 231.34% in root dry weight. Genomic analysis revealed an 8.56-Mb genome (two chromosomes and one plasmid) encoding 7431 genes and 26 secondary metabolite biosynthesis clusters (predominantly nonribosomal peptide synthetases), supporting its capacity for antifungal metabolite secretion, and functional analysis confirmed genes for indole-3-acetic acid (IAA) synthesis, phosphate solubilization, and siderophore production. These results demonstrate that ZBSF BH07 suppresses pathogens via antifungal metabolites and enhances grape growth through phytohormone regulation and nutrient acquisition, providing novel insights into the dual mechanisms of B. gladioli as a biocontrol and growth-promoting agent and laying a scientific foundation for developing sustainable grapevine disease management strategies. Full article

Candida fungal species are the most common fungal opportunistic pathogens. Their ability to form antifungal resistant biofilms contributes to their increasing clinical frequency. These fungi express surface-anchored adhesins including members of the Als family. These adhesins mediate epithelial adhesion, aggregation, and biofilm formation. Many of the adhesins contain cross-β core sequences that form amyloid-like protein aggregates on the fungal surface. The aggregates mediate high-avidity bonding that contributes to biofilm establishment and persistence. Accordingly, autopsy sections from individuals with candidiasis and other mycoses have amyloids within abscesses. An amyloid-forming peptide containing a sequence from Candida albicans Als5 bound to C. albicans, C. tropicalis, and C. parapsilosis. C. albicans and C. tropicalis aggregated with beads coated with serum albumin, and the aggregates stained with the amyloid-binding dye thioflavin T. Additionally, an Als5-derived amyloid-inhibiting peptide blocked cell aggregation. The amyloid-inhibiting peptide also blocked C. albicans, C. tropicalis, and C. parapsilosis adhesion to monolayers of FaDu epithelial cells. These results show the involvement of amyloid-like interactions in pathogenesis in several Candida species. Full article

Anaerobes, the oldest evolutionary life forms, have been unexplored for their potential to produce secondary metabolites due to the difficulties observed in their cultivation. Antimicrobials derived from anaerobic bacteria are an emerging and valuable source of novel therapeutic agents. The urgent need for new antimicrobial agents due to rising antibiotic resistance has prompted an investigation into anaerobic bacteria. The conventional method of antimicrobial discovery is based on cultivation and extraction methods. Antibacterial and antifungal substances are produced by anaerobic bacteria, but reports are limited due to oxygen-deficient growth requirements. The genome mining approach revealed the presence of biosynthetic gene clusters involved in various antimicrobial compound synthesis. Thus, the current review is focused on antimicrobials derived from anaerobes to unravel the potential of anaerobic bacteria as an emerging valuable source of therapeutic agents. These substances frequently consist of peptides, lipopeptides, and other secondary metabolites. Many of these antimicrobials have distinct modes of action that may be able to go around established resistance pathways. To this effect, we discuss diverse antimicrobial compounds produced by anaerobic bacteria, their biosynthesis, heterologous production, and activity. The findings suggest that anaerobic bacteria harbor significant biosynthetic potential, warranting further exploration through recombinant production for developing new antibiotics. Full article

Marine peptides, derived from a great number of aquatic organisms, exhibit a broad spectrum of biological activities that hold a significant therapeutic potential. This article reviews the multifaceted roles of marine peptides, focusing on their antibacterial, antibiofilm, antifungal, antiviral, antiparasitic, cytotoxic, anticancer, immunomodulatory, chemotactic, opsonizing, anti-inflammatory, antiaging, skin-protective, and wound-healing properties. By elucidating mechanisms of their action and highlighting key research findings, this review aims to provide a comprehensive understanding of possible therapeutic applications of marine peptides, underscoring their importance in developing novel drugs as well as in cosmetology, food industry, aquatic and agriculture biotechnology. Further investigations are essential to harness their therapeutic potential and should focus on detailed mechanism studies, large-scale production, and clinical evaluations with a view to confirm their efficacy and safety and translate these findings into practical applications. It is also important to investigate the potential synergistic effects of marine peptide combinations with existing medicines to enhance their efficacy. Challenges include the sustainable sourcing of marine peptides, and therefore an environmental impact of harvesting marine organisms must be considered as well. Full article

The number of fungal infections is steadily increasing, with considerable morbidity and mortality. Additionally, antifungal resistance is a growing concern, highlighting the need to develop new treatment options. One alternative is the use of antimicrobial peptides (AMPs). The aim of this study was to assess the in vitro and in vivo antifungal activity of designed short AMPs, Act-6 and Act 8-20, derived from cecropin transcripts of beetles from the family Scarabaeidae, against eight reference strains of the pathogenic yeasts Candida and Cryptococcus. We also evaluated the effect of these modified AMPs on the biofilm, morphogenesis, and cell morphology of Candida albicans, as well as the in vivo activity via a murine model of disseminated candidiasis. The AMPs herein analyzed exhibit differential antifungal activity against the yeasts assessed, and inhibit biofilm, hyphae, and pseudohyphae formation with morphological alterations in C. albicans. Moreover, the fungal load in mice treated with these AMPs significantly decreased. Altogether, our results suggest that Act-6 and Act 8-20 are promising antifungal molecules to control mycoses. Full article

Bread is consumed daily throughout the world as an important source of nutrients. However, bakery products are highly susceptible to spoilage, especially fungal, which is a source of bread losses and a threat to food security and consumer health. The use of sourdough is the best alternative to chemical preservatives, while providing a number of advantages to baked bread. This review highlights the main areas in the field of bread protection and covers the principal representatives of sourdough microbiota and their contribution to protecting bread from spoilage. The review is mainly based on publications in the field of research over the last five years, identifying new directions and strategies for bread protection related to the use of sourdoughs. A list of the main compounds produced by lactic acid bacteria of the sourdough, which contribute to the protection of bread from fungal spoilage, is presented. The contribution of other microorganisms to the antifungal effect is also considered. Finally, some prospects for the development of research in the field of sourdoughs are determined. Full article

The emergence of antifungal-resistant Aspergillus fumigatus (A. fumigatus) became a serious public health concern, underscoring the need for new effective antifungal agents. Here, we present a strategy based on the in situ generation of radical species that are toxic to the pathogen. The synthesis of an alkoxyamine linked to a peptide substrate recognized by A. fumigatus-secreted dipeptidyl peptidase is described. Kinetic experiments show a stable prodrug prior to enzymatic activation. Ensuing peptide cleavage and spontaneous homolysis resulted in the generation of a stable nitroxide and a reactive alkyl radical moiety. Next, the exposure of A. fumigatus spores to the prodrug lead to pathogen growth inhibition in a compound concentration-dependent fashion (e.g., 42% inhibition at 10 µg/L). Importantly, the designed alkoxyamine inhibited not only the growth of a clinical voriconazole-susceptible A. fumigatus strain, but also the growth of a strain resistant to this azole. To determine the antifungal importance of the reactive alkyl radical, its substitution with a non-radical structure did not prevent A. fumigatus growth. Furthermore, the introduction of succinic group in the peptide substrate resulted in the loss of alkoxyamine antifungal properties. Our work reports a novel chemical strategy for antifungal therapy against A. fumigatus based on the pathogen enzyme-mediated generation of toxic radicals. Significantly, these findings are timely since they could overcome the emerged resistance to conventional drugs that are known to target defined pathogen biologic mechanisms such as ergosterol synthesis. Full article

Introduction: Candidozyma auris (Cz. auris) has emerged globally, and diseases caused by it are associated with a mortality rate of 30–72%. This yeast is often multidrug-resistant and challenging to treat. A synthetic peptide, consisting of 11 amino acids of human lactoferrin (hLF1-11), offers a new therapy that is active against Candida albicans, non-albicans Candida yeasts, as well as Cz. auris. The current study examined the susceptibility of clinically relevant Candida species to hLF(1-11) in vitro and investigated the synergistic interaction of this peptide with fluconazole (FLU) and anidulafungin (ANI). Methods: Susceptibility of the yeasts to hLF(1-11) was tested with a microdilution method to determine minimum inhibitory concentrations (MICs). A total of 59 strains belonging to 16 species of Candida or Candidozyma were tested. The treatment cohort included 20 strains of Cz. auris originating from six different countries. Results: Mean MIC values of all susceptible strains ranged from 16.66 ± 6.46 μg/mL to 45.83 ± 10.21 μg/mL. There were no statistical differences in the susceptibility of hLF(1-11) for Cz. auris across geographic origins. In the combinatory tests, drugs acting together, the fractional inhibitory concentration indexes [FIC] < 1.0, showed a synergistic or additive effect on the efficacy of FLU and ANI when used in combination with hLF(1-11). [FIC] indexes 1–2 were interpreted as intermediate. MIC values in combinatory use were 1–2 titer steps lower than when used alone. Conclusions: hLF(1-11) inhibits the growth of yeasts that belong to the genus Candida, including Cz. auris. The combinatory use may be further investigated to treat infections caused by resistant yeasts. Full article

Nowadays, healthcare systems face two global challenges: the rise of multidrug-resistant pathogens and the growing incidence of cancer. Due to their broad spectrum of activities, antimicrobial peptides emerged as potential alternatives against both threats. Our group previously described the antifungal activity of the α-helical peptide Cm-p5, a derivative of the natural peptide Cm-p1, isolated from the coastal mollusk Cenchritis muricatus; however, its anti-cancer properties remained unexplored. Analyses through calorimetry and molecular dynamics simulations suggest the relevance of phosphatidylserine for the attachment of Cm-p5 to cancer cell membranes. Cm-p5 exhibited cytotoxic activity in a dose-dependent manner against A375 melanoma cells, without toxicity against non-malignant cells or hemolytic activity. DAPI/PI and DiSC3(5) staining confirmed permeabilization, disruption, and depolarization of A375 cytoplasmic membranes by Cm-p5. Furthermore, Annexin V-FITC/PI assay revealed the induction of cellular death in melanoma cells, which can result from the cumulative membrane damage and oxidative stress due to the overproduction of reactive oxygen species (ROS). Moreover, after the treatment, the proliferation of A375 cells was dampened for several days, suggesting that Cm-p5 might inhibit the recurrence of melanomas. These findings highlight the multifunctional nature of Cm-p5 and its potential for treating malignant melanoma. Full article

Lactoferrin (LF) is a natural glycoprotein with strong antimicrobial, immunomodulatory, and nutritional potential and is widely present in milk and mucosal secretions. This paper aims to review the current knowledge on the application of lactoferrin and its bioactive peptides in the context of fungal infections caused by Candida spp., focusing on newborns and pregnant women as high-risk groups. The multifaceted mechanisms of LF action are discussed, including iron chelation, destabilization of fungal cell membranes, and modulation of the immune response. Additionally, data demonstrating the effectiveness of LF in the prevention and supportive treatment of Candida spp. infections are presented. Full article

The World Health Organization (WHO) prioritized 19 fungal species based on the significant impact of these pathogens on human health, including the emergence of antifungal resistance, which highlights the necessity of finding new antifungal therapies. Among these novel therapeutic approaches, the antimicrobial pore-forming peptide C14R has shown to be promising against Candida albicans and Candida auris. In this study, the antifungal in vitro efficacy of C14R was assessed against six additional species from the WHO priority list, Cryptococcus neoformans, Cryptococcus gattii, Candida glabrata, Candida tropicalis, Candida parapsilosis and Candida krusei, as well as against Candida dubliniensis. This study shows that C14R has good antifungal activity against several clinical isolates of the studied species, with MIC values between 0.8476 and 10.88 µg/mL. Most notably, some of the studied isolates are resistant to commonly used antifungal drugs but are susceptible to the peptide. C14R showed, moreover, its capacity to disrupt Cryptococcus capsules, beyond its already proven capacity to disrupt plasma membranes, and its antifungal activity was not affected depending on the serotype or species assessed. The inclusion of basidiomycete and ascomycete yeasts allowed us to display the broad-spectrum potential of C14R, highlighting it as a promising candidate as an antifungal agent. Full article