Epigenetic modulation has emerged as an effective approach to activating silent biosynthetic pathways in fungi and enhancing secondary metabolite production. Nevertheless, little is known about the global molecular processes underlying epigenetic regulation. In the present study, a comparative transcriptomic analysis was performed to investigate the effect of sodium valproate, an epigenetic modifier, on Macrophomina phaseolina. RNA sequencing generated high-quality reads in both control (R7BA control) and treated (R7BA-treated) samples, and differential gene expression analysis revealed significant transcriptional reprogramming in response to epigenetic treatment. A total of 461 genes were significantly upregulated, and 533 genes were significantly downregulated (FDR < 0.05). The upregulated genes were mainly associated with oxidoreductase activity, detoxification enzymes, transporters, and secondary metabolite biosynthesis, including cytochrome P450, cytochrome b5, short-chain dehydrogenase/reductase, glutathione S-transferase, and ABC transporters. In contrast, downregulated genes were primarily related to carbohydrate metabolism, nutrient acquisition, signal transduction, and primary metabolic processes. Gene Ontology analysis revealed dominance of catalytic activity, nucleotide binding, and transport activity, while KEGG pathway analysis indicated enrichment in translation, carbohydrate metabolism, amino acid metabolism, transport and catabolism, and energy metabolism pathways. qRT-PCR validation of selected differentially expressed genes confirmed the reliability of RNA-seq results. Overall, the study demonstrates that epigenetic treatment induces global transcriptional reprogramming and redistribution of metabolic pathways, leading to activation of secondary metabolism. These findings provide important insights into the molecular basis of epigenetic regulation and highlight its potential to activate silent gene clusters and discover novel bioactive secondary metabolites in fungi.

Biological control has emerged as an alternative approach for mitigating plant diseases and minimizing the disproportionate use of agrochemicals and their hazardous impacts. Myxobacteria, a group of swarming soil bacteria, owing to their predatory mechanisms, are of particular interest such as their biocontrol potential. The present study investigates the antagonistic potential of myxobacteria isolated from various eco-geographical regions of India against phytopathogenic fungi, including Sclerotinia sp., Colletotrichum capsici, Aspergillus flavus, Fusarium solani, and Fusarium oxysporum. Myxococcus fulvus (ST/P/71) isolate exhibited significant broad-range antagonistic activity. ST/P/71 extract demonstrated antifungal activity against F. solani and inhibited biofilm formation by both F. solani and A. flavus. The ST/P/71 isolate was also observed to produce cell wall-degrading enzymes and the antifungal secondary metabolite myxothiazole A, suggesting their micro-predation capabilities against phytopathogens.

Trichoderma species exhibit remarkable versatility in adaptability and in occupying habitats with lifestyles ranging from mycoparasitism and saprotrophy to endophytism. In this study, we present the first high-quality whole-genome assembly and annotation of T. lixii using Illumina HiSeq technology to explore the mechanisms of endophytic lifestyle and plant colonization. The genome size was 41.1 Mbp, comprising 15,430 predicted genes, of which 7,918 were functionally annotated. Comparative analysis identified 82 CAZyme families involved in cellulose and hemicellulose degradation, notably Glycoside Hydrolases (GHs) (43) [e.g., GH3 (14), GH5 (10), GH7 (4) ], Carbohydrate Esterases (CEs) (10), and Auxiliary Activities (AAs) (29) [e.g., AA3 (20), AA9 ]. GHs primarily degrade cellulose, while Polysaccharide Lyases (PLs), along with other CAZymes like CEs and Lytic Polysaccharide Monooxygenases (LPMOs), assist in modifying substrates or targeting specific bonds. These enzymes facilitate substrate breakdown, host tissue penetration, and nutrient acquisition, supporting a non-pathogenic, endophytic lifestyle. The presence of 53 secondary metabolite biosynthetic gene clusters indicates a strong biosynthetic potential. KEGG analysis assigned 2,469 genes to multiple metabolic and signaling pathways, highlighting an enriched profile for carbohydrate metabolism, signal transduction, and antibiotic biosynthesis. Comparative genomics also revealed both preserved and distinctive traits of T. lixii, confirming its ecological flexibility and promise as a source of new bioactive molecules. These findings reveal genetic diversity among the species, providing a foundation for future studies on biocontrol and endophytic functions. The growing availability of Trichoderma genomes deepens understanding of their unique features and offers new prospects for agricultural and biotechnological applications.

Apples are among the most popular nutritious fruits. They are prone to several postharvest fungi, resulting in significant losses in overall production. This study evaluated the potential of developed gel formulations (soft gel and carrageenan-guar gum gel) incorporated with combinations of Monarda citriodora essential oil (MEO) and linalool to control the postharvest black spot rot of apples and to improve their shelf life. The pathogenic fungus was isolated from infected apples and characterised as Alternaria angustiovoidea. In vitro, minimum fungicidal concentrations of MEO, hexanal, and linalool vapour phase showed activity at 1346.15 µL L−1 air, 192.30 µL L−1 air and 192.30 µL L−1 air concentration, respectively. MEO and linalool's in vitro checkerboard assay showed synergy, while the combination of MEO and hexanal was additive. In vivo, the checkerboard assay with MEO and linalool incorporated in soft gel formulation showed a synergistic effect at W3 (MEO 336.54 μL L−1 air and linalool 48.07 μL L−1 air) and X3 (MEO 336.54 μL L−1 air and linalool 24.03 μL L−1 air). The soft gel formulation prevented the pH and total soluble solids of the stored apples from changing, inhibited the breakdown of ascorbic acid, and decreased weight loss. Additionally, the stored apples' total phenolic content and antioxidant activity enhanced. The synergistic combination of MEO and linalool incorporated in soft gel formulation could be a promising postharvest treatment against black spot rot of apples for extended shelf life and for maintaining apple fruit quality during storages.

The present study examined the antifungal activity of Monarda citriodora essential oil (MEO) and transcinnamaldehyde (trans-c) vapours on Aspergillus fijiensis (C4), a new causative agent of postharvest rot of lemon. The disc fumigation method was used to assess the in vitro Minimum Fungicidal Concentrations (MFCs); the MFCs for MEO was 961.53 mu L L -1 air, and for trans-c, 96.15 mu L L -1 air. The in vitro checkerboard assay showed synergy at two concentrations viz. 240.38 mu L L -1 air of MEO +24.03 mu L L -1 air of trans-c (N2) and 240.38 mu L L -1 air of MEO + 12.015 mu L L -1 air of trans-c (O2). The In vivo fumigation with N2 and O2 combinations showed complete inhibition of C4 growth on lemons till seven days post-treatment at 24 +/- 2 degrees C. The vapours showed no significant changes in the weight loss, ascorbic acid content, pH and total soluble solids of treated lemons. Propidium iodide staining and ergosterol content analyses showed that the vapour treatments damaged the fungal plasma membrane, which led to cytoplasmic material leakage. SEM analysis revealed the vapour treated C4 mycelia to be rough, broken and squashed. Overall, our results indicate that the MEO and trans-c vapours irreversibly damage the plasma membrane of A. fijiensis and could be exploited for the postharvest storage of lemons.

Chemical investigation of endophytic fungal extract of Aspergillus fumigatus strain KF436391 isolated from medicinal plant Monarda citriodora yielded one new compound 2-methylenedecanedioic acid (1) along with seventeen known compounds (2-18) including (E)-Undec-2-enedioic acid (2), Ergosterol (3) Ditryptophenaline (4), Gliotoxin (5), Pseurotin A (6), 12, 13-dihydroxyfumitremorgin C (7), Brevianamide F (8), Demethoxy fumitremorgin C (9), Fumitremorgin C (10), Bisdethiobis (methylthio) gliotoxin (11), Cephalimysin A (12), Neofipiperazine C (13), Antibiotic FD838 (14), Monomethylsulochrin (15), trans-p-coumaric acid (16), trans-ferulic acid (17) and 6-Methoxyspirotryprostatin B (18). Anticancer evaluation study of all the compounds against a panel of eleven human tumor cell lines (PC-3, HT-29, MCF-7, OVCAR-5, HCT-15, SF-268, A549, HCT-116, SW620, T47D and MD-MBA-435) of varied tissue origin revealed that compound 5 found to be the most potent cytotoxic agent against all the cancer cell lines examined, with an IC50 value <1.0 mu M. But, it also showed cytotoxicity for normal human cells. Compounds 12, 14 and 15 exhibited maximum cytotoxicity against colon (HT-29) cancer cell line with IC50 values 2.2, 2.8 and 7.7 mu M respectively and were nontoxic for normal human cells(.) Docking studies of all the isolated compounds carried out using the Gaussian 09 suite of programs at B3LYP/6-31+G(d) level of theory against three different proteins Poly [ADP-ribose] polymerase-1 (ID: 1UK0), TRAF2 (ID: 2X7F) and Matrix Metalloproteinase-2 (ID: 1HOV) and maximum binding affinity was observed for TRAF2 (2X7F) protein. The in silico and in vitro anticancer results revealed that compounds 14 and 15 have the potential to be developed as anticancer agents against colon cancer cells.

This study aims to isolate endosymbiontic fungi from the marine sponge Lamellodysidea herbacea and to explore their antioxidant potential. Marine-derived fungi, with their vast biodiversity, are considered a promising source of novel antioxidants which can replace synthetic ones. Marine sponges have previously reported bioactive properties that could ameliorate oxidative stress, particularly their associated fungi, producing high-frequency bioactive molecules (adaptogenic molecules) in response to stressors. 19 endosymbiont fungi associated with marine sponges were isolated, and their extracts were evaluated for their antioxidant capacities. Extract of an endosymbiont fungus, isolate SPG6, identified as Alternaria destruens, through surface electron microscopy (SEM) and ITS gene sequencing, showed broad range antioxidant activities (EC50 values) (free radical scavenging 32.54 mg L−1, Hydroxyl radical scavenging activity < 0.078 g L−1, total reducing power 0.114 g L−1, Chelating power 0.262 g L−1, H2O2 scavenging activity < 0.078 g L−1, and Superoxide radical scavenging activity > 5.0 g L−1). The extract of isolate SPG6 was fractioned and analyzed through GC–MS. Marine sponge-associated endosymbiont fungi are a rich source of antioxidant molecules.

Infected leaves were collected from the field, and the causative pathogen was isolated. The pathogen was identified through morphological studies and ITS of rRNA sequencing as Alternaria sp. Monarda citriodora essential oil (MEO) and isoeugenol showed a minimum inhibitory concentration of 312.5 μg/mL and 156.25 μg/mL, respectively, against the isolated pathogen. Synergistic interaction was observed in the combination of MEO-isoeugenol with a fractional inhibitory concentration index of 0.49. The MEO-isoeugenol combination showed a significant curative and protective effect against the isolated pathogen in the glasshouse pot study.

Background: The increased reliance on synthetic fungicides for managing postharvest pathogens resulted in the rise of fungicide-resistant pathogen strains. Previous studies have reported essential oils (EOs) as a promising alternative to synthetic fungicides. However, higher concentrations are required for their practical application, which can alter the taste profile of the stored pro-duce. Synergistic combinations of EO volatiles can reduce the active concentrations, thereby mitigating undesirable taste profile changes. However, very few studies have emphasised the changes in the mode of action of EO volatiles when applied as a synergistic combination. This study aimed to decipher the mode of action of Monarda citriodora essential oil (MEO) and hexa-nal vapour combination (M + H) against the newly identified postharvest pathogen of apple As-pergillus foetidus.Results: The M + H vapour treatment synergistically inhibited the spore germination of A. foetidus at the concentration of 144.23 mu L L-1 air (MEO) and 96.15 mu L L-1 air (hexanal). Pro-pidium Iodide staining and ergosterol content analysis revealed that vapours compromised the plasma membrane integrity. Hence, there was an extracellular leakage of cytoplasmic compo-nents, reduced extracellular pH and increased conductivity. Furthermore, calcofluor white staining showed reduced fluorescence intensity, indicating a compromised cell wall. Reduced chitin content in the cell walls of vapour treated mycelia authenticated the results. 2 ',7 '-Dichlorofluorescin diacetate (DCFDA) staining revealed the generation and accumulation of Re-active Oxygen Species (ROS) within the vapour treated mycelia.Conclusion: The accumulated ROS interferes with ergosterol and chitin synthesis leading to the collapse of the plasma membrane and cell wall; consequently, extracellular leakage occurs.

Background: Cryptosporidiosis caused by Cryptosporidium spp. is a zoonotic disease and is the most prevalent pathogens worldwide and leads to severe diarrhoeal diseases and affects the immunological status of the individual. Thus, the study was undertaken to examine the anti-cryptosporidial efficacy of curcumin in comparison with ethanolic extract of curcuma longa in immunocompromised mice infected with oocysts isolated from cattle calves of Jammu region and identified as Cryptosporidium parvum using nested PCR on small subunit ribosomal ribonucleic acid (SSU rRNA) gene. Methods: Two hundred female Swiss albino mice were equally divided into ten groups. Group I were kept as a healthy control, group II were immunocompromised, group III were immunocompromised and infected, group IV animals were immunocompromised, infected and treated orally with nitazoxanide. Animals in groups V to VII were immunocompromised, infected and treated with ethanolic extract of C. longa @ 4, 6 and 8 mg/kg/day/os respectively whereas groups VIII to X were immunocompromised, infected and treated with pure salt of curcumin @ 4, 6 and 8 mg/kg/day/os respectively for 5 successive days. Thus, mean oocysts per gram faeces, body weight gain and histopathological changes were measured in different groups. Result: Administration of curcumin as a therapeutic agent @ 8 mg/kg body weight for five days resulted in higher percent mean oocyst reduction of 74.03% and improved body weight gain in experimentally infected mice. Histopathological changes showed that treatment with oral curcumin (group X) in animals had minimal and improved intestinal lesions as compared to animals treated with C. longa (group VII). Altogether, curcumin showed promising anticryptosporidial effects under in vivo conditions and deserves further exploration.

One of the biggest global causes of death is cancer. The side effects of currently available therapies have triggered the search for new drugs. The marine environment, with its vast biodiversity, including sponges, is a rich source of natural products with immense pharmaceutical potential. The aim of the study was to analyze the microbes associated with the marine sponge, Lamellodysidea herbacea, and explore them as resources for anticancer ability. This study includes the isolation of fungi from L. herbacea, and their evaluation for cytotoxic potential against human cancer cell lines such as A-549 (lung), HCT-116 (colorectal carcinoma), HT-1080 (Fibrosarcoma), and PC-3 (prostate) using MTT assay. This revealed that fifteen extracts showed significant anticancer ability (IC50 ≤ 20 µg/mL), at least against one of the cell lines. Three extracts, SPG12, SPG19, and SDHY 01/02, were found significant in terms of anticancer activity, at least against three to four cell lines (IC50 values ≤ 20 µg/mL). The fungus SDHY01/02 was identified by sequencing the internal transcribed spacer (ITS) region as Alternaria alternata. Its extract showed IC50 values < 10 µg/mL against all the tested cell lines and was further analysed through light and fluorescence microscopy. The extract of SDHY01/02 was active (lowest IC50 4.27 µg/mL) against A549 cells in a dose-dependent manner and caused apoptotic cell death. Further, the extract was fractionated and analyzed the constituents by GC-MS (Gas Chromatography-Mass Spectrometry). Di-ethyl ether fraction revealed the constituents (having anticancer activity) such pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl); 4,5,6,7-tetrahydro-benzo[C]rhiophene-1-carboxylic acid cyclopropylamide; 17-pentatriacontene; 9,12-octadecadienoic acid (Z, Z)-, methyl ester; while DCM fraction contained Oleic acid, eicosyl ester. This is the first report of A. alternata with anticancer potential that has been isolated from the sponge L. herbacea, as far as we are aware.This A. alternata can be exploited to get anticancer molecule(s) in the future.

Aims Citrus limon (lemon) is a widely cultivated citrus fruit. Significant postharvest losses due to fungi plague its production. Environmental and human health hazards have made the application of synthetic fungicides unsuitable. Despite the previous reports of antifungal activities of essential oil (EO) vapors, their synergistic combinations are understudied. Synergistic vapor combinations are advantageous due to less concentration of active components. This study aimed to isolate and identify postharvest fungal pathogens lemon and to evaluate the antifungal effects of synergistic Monarda citriodora EO (MEO)-constituent vapor combinations in vivo and in vitro.Methods and results Postharvest fungal pathogens of lemon (C. limon) were isolated from various infected samples. The most pathogenic isolate was identified through morphology and its ITS-based rRNA gene sequencing as Aspergillus foetidus (O4). This is the first report of A. foetidus as a postharvest pathogen of lemon. The minimum fungicidal concentrations (MFCs) of MEO vapors treatment against O4 were 1346.15 mu L/L air. For carvacrol, hexanal, and linalool, MFC was same (96.16 mu L/L air). Checkerboard assays demonstrated that 1/4 MFC of MEO (336.54 mu L/L air) and 1/4 MFC of linalool (24.04 mu L/L air) (M + L) were synergistic against O4. M + L vapors reduced the O4 growth on lemons during storage by 64% +/- 1.50% and preserved their quality (low weight loss %, unchanged pH, increased ascorbic acid content). Propidium iodide staining, ergosterol content analysis, calcofluor white staining and chitin content analysis revealed the integrity loss of the O4 plasma membrane and cell wall. 2 ',7 '-Dichlorofluorescin diacetate staining revealed accumulation of intracellular reactive oxygen species (ROS), and scanning electron microscopy (SEM) analysis exposed the M + L treated mycelia with malformations.Conclusions M + L vapors offer protection for lemons from A. foetidus and preserve their quality during storage.

Apples are susceptible to various fungal infections following harvest, resulting in significant losses. This study aimed to develop an essential oil based gel formulation to control the postharvest rot of apples caused by Aspergillus foetidus CBS121.28 and increase their shelf life during storage. In vitro, minimal fungistatic and fungicidal doses of MEO and constituents acting in the vapour-phase were established. MFC (Minimum Fungi-cidal Concentration) for MEO was 1153.85 mu L L-1 air, hexanal 384.62 mu L L-1 air, and carvacrol 96.15 mu L L-1 air. The combinatorial treatment of MEO and constituents indicated synergy (FICI 0.375) between MEO (144.23 mu L L-1 air) and hexanal (96.15 mu L L-1 air). In contrast, the combination of MEO and carvacrol was antagonistic. In vivo treatment of MEO and hexanal combination on apple fruit by direct fumigation resulted in phytotoxicity. However, the phytotoxicity was remediated using the gel formulations incorporating various concentrations of MEO and hexanal combinations (Carrageenan guar gum gel and soft gel), which showed a synergistic effect (FICI 0.25 and 0.375, respectively). The gel formulations reduced the weight loss, suppressed the degradation of ascorbic acid, and prevented the change of pH and total soluble solids of the stored apples. The antioxidant activity and total phenolic content also increased in the stored apples. These findings suggest that using MEO and hexanal in a gel formulation is a more effective and organic way to protect apples from Aspergillus rot for an extended storage period.

Aims This study aimed to develop essential oil-containing biopolymer-based vapor gel formulations for the postharvest management of blue mould of apples. Apples are one of the widely cultivated fruits. They are susceptible to a wide range of fungus leading to high losses in overall production. Many research articles have highlighted the applications of essential oil-biopolymer coatings in the postharvest storage of fruits. However, no studies have yet tried to explore the potential of a vapour gel formulation for postharvest applications. Methods and results Contaminated apples were collected from the local market. The causative fungus was isolated and identified. Minimum fungicidal concentrations of Monarda citriodora essential oil (MEO) and hexanal/linalool in the vapour phase were determined in vitro. In vitro and in vivo, checkerboard assays were used to demonstrate the synergistic activity between MEO and hexanal/linalool vapours against the isolated pathogen. MEO and linalool (M + L) combinatorial treatment indicated synergy in vivo and in vitro. In vivo treatment of M + L on apples by direct fumigation showed phytotoxicity. Gel formulations (carrageenan-guar gum, carbopol gel, and soft gel) were developed and evaluated to address phytotoxicity. M + L combination synergistically remediated the phytotoxicity in both carbopol (FICI = 0.625) and soft gels (FICI = 0.5625). The physicochemical parameters (pH, weight loss, TSS, and ascorbic acid (AsAC) of the treated apples were analysed. Reduction in weight loss and increase in AsAC were observed for treated fruits when compared to control, and no change in pH and TSS was observed. Conclusions Biopolymer vapour gel formulations containing M + L vapours effectively protect apples from the postharvest blue mould for extended storage.

Natural value-added compounds produced from biological sources have attained immense significance in medicinal, food, flavourings, and agrochemical industries. Further, biotransformation is a powerful tool used to produce value-added compounds cost-effectively and selectively. In the present study, biotransformation of eugenol using an endophytic fungus Daldinia sp. IIIMF4010 isolated from the fresh leaves of the plant Rosmarinus officinalis leads to the production of two known value-added compounds. The biotransformation reaction of eugenol (50 mM) resulted in the production of eugenol-β-D-glucopyranoside (6.2%) and vanillin (21.8%). These biotransformed products were further characterized by liquid chromatography-mass spectroscopy (LC-MS) and nuclear magnetic resonance (NMR).

Endophytic fungi are rich sources of structurally complex chemical scaffolds with interesting biological activities. However, their metabolome is still unknown, making them appealing for novel compound discovery. To maximize the number of secondary metabolites produced from a single microbial source, we used the “OSMAC (one strain–many compounds) approach.” In potato dextrose medium, M. phaseolina produced phomeolic acid (1), ergosterol peroxide (2), and a volatile compound 1,4-benzene-diol. Incorporating an epigenetic modifier, sodium valproate, affected the metabolite profile of the fungus. It produced 3-acetyl-3-methyl dihydro-furan-2(3H)-one (3) and methyl-2-(methyl-thio)-butyrate (4), plus volatile chemicals: butylated hydroxy toluene (BHT), di-methyl-formamide, 3-amino-1-propanol, and 1,4-benzenediol, 2-amino-1-(O-methoxyphenyl) propane. The structure of compounds 1–4 was established with the help of spectroscopic data. This study revealed first-time compounds 1–4 in the fungus M. phaseolina using a classical and epigenetic manipulation approach.

In the present work, piperic acid and 4-ethylpiperic acid (EPA) amides with amino acids ( C1–C8 ) were bio-evaluated for their antimicrobial activity and biofilm inhibition against Gram-positive and Gram-negative bacterial strains. Among all, EPA-β 3,3 -Pip(Bzl)-OMe, C2 displayed the potent antimicrobial activity with MIC of 6.25 μg ml –1 against Gram-negative bacteria Escherichia coli . In combination studies, the FIC indices suggested that C1 and C2 have a synergistic effect with ciprofloxacin against E. coli and Bacillus subtilis , whereas C5 exhibited a synergistic effect with ciprofloxacin against all the tested bacteria. The inhibitory effect of amides C1 , C2 , and C5 on the biofilm formation of test strains was significantly potentiated by co-administration with ciprofloxacin. Furthermore, the effective concentrations of C2 in combination reduced drastically compared to alone for biofilm inhibition. At these concentrations, C2 showed negligible hemolytic and cytotoxic activities.

Development of acaricidal resistance and environmental pollution has driven need for eco-friendly pesticides and herbal acaricides. Rhizome extracts of Curcuma longa in three different solvents (acetone, chloroform and ethanol) were used in the range of 0.625-10.0% for larval immersion test against unfed larvae of Rhipicephalus microplus ticks. HPLC-PDA chromatogram showed peak of Bis demethoxy curcumin, Demethoxy curcumin and Curcumin at 430 nm with the retention time of 14.502, 15.840 and 17.33 min, respectively, in a standard marker preparation and in the sample. Ethanolic extract showed much higher yield of Demethoxy curcumin and Curcumin in comparison to acetone and chloroform extracts. Mortality rates of larval ticks were in dose-dependent manner and 100% mortality of tick larvae was achieved at 10% concentration for acetone and chloroform extracts whereas ethanolic extract showed 100% mortality of tick larvae from 7.5% concentration onwards. Among the three extracts, the highest acaricidal activity was shown by ethanolic extract with 2.43%, 9.12%, 13.26% and 26.77% values of LC50, LC90, LC95 and LC99, respectively. Significant larvicidal activity of C. longa rhizome extracts against unfed larvae of R. microplus qualifies them as green pesticides which could be combined with other tools for integrated pest management.

The present work describes the synthesis of hybrid dipeptides H-Lys-Gpn-PEA, C1; H-Lys-β3,3AC6C-PEA, C2, and THPA conjugated dipeptides, THPA-Lys-Gpn-PEA, C3, and THPA-Lys-β3,3AC6C-PEA, C4. All the peptides were evaluated against both Gram-negative and Gram-positive bacterial strains. Among all, peptide C4 exhibited the most potent activity with MIC 1.56 μM against P. aeruginosa (MTCC 424) and S. aureus (MTCC 737). Further, time-kill kinetics, fluorescence assays, and scanning electron microscopy (SEM) studies were performed in order to understand the mechanism of action and efficacy of peptide C4, The fluorescence assays and SEM images demonstrated the bacterial killing through membrane disruption. The peptide C4 exhibited very low hemolytic activity with negligible cytotoxicity against normal human breast cell line FR2.