Biosynthesis of silver nanoparticles (AgNPs) is emerging as a simple and eco-friendly alternative to conventional chemical synthesis methods. The role of AgNPs is expanding as antimicrobial and anticancer agents, sensors, nanoelectronic devices, and imaging contrast agents. In this study, biogenic AgNPs were synthesized using extracts of different marine algae species, including Ulva rigida (green alga), Cystoseira myrica (brown alga), and Gracilaria foliifera (red alga), as reducing and capping agents. The Physiochemical properties, cytotoxicity, anticancer and antimicrobial activities of the biosynthesized AgNPs were assessed. Surface plasmonic bands of the biosynthesized AgNPs capped with U. rigida, C. myrica, and G. foliifera extracts were visually observed to determine a colour change, and their peaks were observed at 424 nm, 409 nm, and 415 nm, respectively, by UV–Vis spectroscopy; transmission electron microscopy (TEM) indicated an almost spherical shape of AgNPs with nanoscale sizes of 12 nm, 17 nm, and 24 nm, respectively. Fourier transform-infrared (FTIR) spectroscopy analysis suggested that different molecules attached to AgNPs through OH, C=O, and amide groups. The major constituents of the aqueous algal extracts included, terpenoids, polyphenols, sulfonates, polysaccharides, fatty acids, chlorophylls, amide proteins, flavonoids, carotenoids, aliphatic fluoro compounds, volatile compounds, alkalines, pyruvic acid and agar groups. The cytotoxicity and anticancer activities of the biosynthesized AgNPs were assessed using Artemia salina nauplii, normal skin cell lines (HFb-4), and breast cancer cell lines (MCF-7 cell line). The lethality was found to be directly proportional to the AgNP concentration. The IC₅₀ values of C. myrica and G. foliifera AgNPs against A. saline nauplii were 5 and 10 μg ml⁻¹ after 4 h and 16 h, respectively, whereas U. rigida AgNPs did not exhibit cytotoxic effects. Anticancer activity of the biosynthesized AgNPs was dose dependent. The IC₅₀ values of the biosynthesized AgNPs were 13, 13, and 43 µg ml⁻¹ for U. rigida, C. myrica, and G. foliifera, respectively. U. rigida AgNPs particularly exhibited potent anticancer activity (92.62%) against a human breast adenocarcinoma cell line (MCF-7) with high selectivity compared the normal cells (IC₅₀ = 13 µg/ml, SI = 3.2), followed by C. myrica AgNPs (IC₅₀ = 13 µg/ml, SI = 3.07). Furthermore, the biosynthesized AgNPs exhibited strong antifungal activity against dermatophyte pathogenic moulds and mild antibacterial activity against the food borne pathogen bacteria. The highest antimicrobial activity was recorded for the U. rigida AgNPs, followed by those capped with C. myrica and G. foliifera extracts, respectively. AgNPs capped with the U. rigida extract exhibited the highest antimicrobial activity against Trichophyton mantigrophytes (40 mm), followed by Trichosporon cataneum (30 mm) and E. coli (19 mm), with minimal lethal concentration of 32 and 64 μg ml⁻¹ respectively. The study finally revealed that extracts of marine algal species, particularly U. rigida extracts, could be effectively used as reducing agents for the green synthesis of AgNPs. These AgNPs are considered efficient alternative antidermatophytes for skin infections and anticancer agents against the MCF-7 cell line.

Microbial biopolymers have emerged as promising solutions for environmental pollution-related human health issues. Poly-γ-glutamic acid (γ-PGA), a natural anionic polymeric compound, is composed of highly viscous homo-polyamide of D and L-glutamic acid units. The extracellular water solubility of PGA biopolymer facilitates its complete biodegradation and makes it safe for humans. The unique properties have enabled its applications in healthcare, pharmaceuticals, water treatment, foods, and other domains. It is applied as a thickener, taste-masking agent, stabilizer, texture modifier, moisturizer, bitterness-reducing agent, probiotics cryoprotectant, and protein crystallization agent in food industries. γ-PGA is employed as a biological adhesive, drug carrier, and non-viral vector for safe gene delivery in tissue engineering, pharmaceuticals, and medicine. It is also used as a moisturizer to improve the quality of hair care and skincare cosmetic products. In agriculture, it serves as an ideal stabilizer, environment-friendly fertilizer synergist, plant-growth promoter, metal biosorbent in soil washing, and animal feed additive to reduce body fat and enhance egg-shell strength.

This study investigated different amino acid-based surfactants (AASs), also known as biosurfactants, including sodium N-dodecyl asparagine (AS), sodium N-dodecyl tryptophan (TS), and sodium N-dodecyl histidine (HS) for their potential anticorrosion, antibacterial, and antidermatophyte properties. The chemical and electrochemical techniques were employed to examine the copper corrosion inhibition efficacy in H₂SO₄(1.0 M) solution at 298 K. The results indicated their promising corrosion inhibition efficiencies (% IEs), which varied with the biosurfactant structures and concentrations, and the concentrations of corrosive medium. Higher % IEs values were attributed to the surfactant adsorption on the copper surface and the production of a protective film. The adsorption was in agreement with Langmuir adsorption isotherm. The kinetics and mechanisms of copper corrosion and its inhibition by the examinedAASswere illuminated. The surfactants behaved as mixed-kind inhibitors with minor anodic priority. The values of % IEs gained from weight loss technique at a 500 ppm of the tested surfactants were set to be 81, 83 and 88 forAS, HSandTS, respectively. The values of % IEs acquired from all the applied techniques were almost consistent which were increased in the order:TS > HS ≥ AS, establishing the validity of this study. These surfactants also exhibited strong broad-spectrum activities against pathogenic Gram-negative and Gram-positive bacteria and dermatophytes.HSexhibited the highest antimicrobial activity followed byTS, andAS. The sensitivity of pathogenic bacteria varied against testedAASs.Shigella dysenteriaeandTrichophyton mantigrophyteswere found to be the most sensitive pathogens.HSexhibited the highest antibacterial activity againstShigella dysenteriae, Bacillus cereus, E. coli,K. pneumoniae,andS. aureusthrough the formation of clear zones of 70, 50, 40, 39, and 35 mm diameters, respectively.AASsalso exhibited strong antifungal activity against all the tested dermatophyte molds and fungi.HScaused the inhibition zones of 62, 57, 56, 48, and 36 mm diameters againstTrichophyton mantigrophytes,Trichophyton rubrum, Candida albicans, Trichosporon cataneum,andCryptococcus neoformans, respectively.AASsminimal lethal concentrations ranged between 16 to 128 µg/ml.HSpresented the lowest value (16 µg/ml) against tested pathogens followed byTS(64 µg/ml), andAS(128 µg/ml). Therefore,AASs, especiallyHS,could serve as an effective alternative antimicrobial agent against food-borne pathogenic bacteria and skin infections-associated dermatophyte fungi.

Probiotics are commensals with special characteristics that are essential for the development of the immune system, and may protect mucosal surfaces against pathogens. In this study, a total of 40 lactic acid bacteria (LAB) were isolated from different raw and fermented camel’s milk samples collected from Saudi Arabia (Makkah area) and Egypt (Fayoum), and tested for the probiotic properties. Among them, Pro 4 and Pro 7 isolates exhibited excellent probiotic potential including bile salt (0.2–0.6%), phenol tolerance (0.2–0.4%) and salt tolerance (0.0–10%). Furthermore, both strains exhibited antimicrobial activity against wide range of food-borne pathogens and Dermatophytes with average zone inhibition of 37.5, 35.5, 34.5, 27.5, 25 and 23.5 mm for Staphylococcus aureus, Trichophyton mentagrophytes, Escherichia coli, Listeria monocytogens, Candida albicans and Salmonella typhi, respectively. Furthermore, the in vivo study indicated that these strains significantly improved the mucosal immune responses through an increase in expression of TLR2 and IFNγ mRNA in mice intestine as well as increased the synthesis of polyclonal IgG, IgM and IgA in mice blood sera. Accordingly, due to these unique probiotic properties, both selected strains could be potentially used as probiotic starter cultures for fermented dairy foods as well as functional food and health products.