| Titre : | Biogenic synthesis of Nanocopper particles and their applications |
| Auteurs : | MOULAI Rania, Auteur ; MOKHTARI Hounaida, Auteur ; Mohamed Amine Gacem, Directeur de thèse |
| Type de document : | texte imprimé |
| Editeur : | Dr. Moulay Tahar Université Saida, Faculté des Sciences Naturelles et de la Vie, 2024/2025 |
| Format : | 87 p / 29 CM |
| Accompagnement : | CD |
| Langues: | Anglais |
| Langues originales: | Anglais |
| Catégories : | |
| Mots-clés: | Biogenic synthesis ; Copper oxide nanoparticles ; Streptomyces sp. T003 ; Antifungal activity ; Antioxidant activity ; Plant growth promotion ; Nanotechnology |
| Résumé : |
This research investigates the biogenic synthesis, structural characterization, and bio-
agronomic potential of calcium-doped copper nanostructures (Ca@CuO@Cu) produced via a green route mediated by the metabolites of Streptomyces sp. T003. The study was designed to bridge microbiology, nanotechnology, and plant pathology, aiming to develop eco-friendly nanomaterials capable of replacing conventional chemical fungicides and fertilizers. The Streptomyces strain T003 was successfully revived and characterized on GYM and CSA media, showing abundant aerial and substrate mycelia, sporulation, and strong pigment diffusion typical of highly active actinobacteria. Simultaneously, three major phytopathogenic fungi Fusarium oxysporum, Rhizoctonia solani, and Phytophthora infestans were isolated and identified through their cultural and microscopic traits, representing the main soil-borne and foliar diseases affecting tomato crops.The green synthesis of calcium-doped copper nanostructures was visually evidenced by the characteristic color transition from blue to dark brown or black, indicating the reduction of Cu²⁺ to Cu⁰/Cu₂O. UV–Visible spectroscopy revealed a broad surface plasmon resonance (SPR) band at 540– 590 nm, confirming metallic copper formation. XRD analysis showed crystalline peaks corresponding to monoclinic CuO (JCPDS 45-0937), metallic Cu (JCPDS 04-0836), and minor CaO/CaCO₃ reflections, demonstrating the successful formation of a hybrid Ca@CuO@Cu structure. FTIR spectra indicated the presence of hydroxyl, carbonyl, and Cu–O vibrations associated with Streptomyces- derived biomolecules acting as reducing and capping agents. SEM micrographs revealed irregularly shaped nanoparticles with an average size of 260–270 nm.Biological assays confirmed a multifunctional activity spectrum. Calcium-doped copper nanostructures exhibited strong antifungal effects in a dose-dependent manner, with Phytophthora infestans being the most sensitive, followed by Fusarium oxysporum and Rhizoctonia solani. Antioxidant activity, assessed by the DPPH assay, showed an inverse dose- response: nearly 100 % radical scavenging at 0.1 mg·mL⁻¹ but declining at higher concentrations due to nanoparticle aggregation and possible pro-oxidant ROS generation. Insecticidal tests demonstrated time- and dose- dependent lethality, reaching 100 % mortality above 1 mg·mL⁻¹ (LC₅₀ ≈ 0.6–0.8 mg·mL⁻¹ after 72 h).Agronomic experiments using tomato (Solanum lycopersicum L.) seedlings revealed that low to moderate calcium-doped copper nanostructures concentrations (0.5– 0.75 mg·mL⁻¹) significantly enhanced root and shoot growth, chlorophyll synthesis, and biomass accumulation, whereas higher concentrations (≥ 1 mg·mL⁻¹) induced phytotoxic effects through oxidative stress. In greenhouse trials, foliar spraying of Ca@CuO@Cu (0.1 g·L⁻¹) ten days after fungal inoculation substantially reduced wilting, necrosis, and leaf blight, while improving overall plant vigor compared to both infected controls and chemically treated plants.Collectively, the results demonstrate that biogenic Ca@CuO@Cu produced by actinomycetes combine antifungal, antioxidant, insecticidal, and plant-growth-promoting properties, offering a sustainable alternative to synthetic agrochemicals and paving the way for their integration into environmentally responsible crop protection programs. |
| Note de contenu : |
Introduction
Literature Review Actinomycetes History Definition Characteristics of actinomycetes Morphology of actinomycetes Physiology Chemical characteristics Cell wall composition DNA structure Ecology and distribution of actinomycetes Actinomycetes in Soil Actinomycetes in Marine Actinomycetes in Air Thermophilic actinomycetes Pathogenic actinomycetes Isolation methods of actinomycetes Identification of actinomycetes Nutritional aspects Taxonomy and classification of actinomycetes Role of actinomycetes Antibiotic production Ecological role Medical impact Industrial uses Unique biological features Agricultural applications Ongoing research Developmental cycle of actinomycetes Aerial mycelium Substrate mycelium Metabolism of actinobacteria Future perspective on actinomycetes Biogenic synthesis of copper nanoparticles and their applications Historical background Rationale for biogenic production of copper nanoparticles Eco-friendly and sustainable Cost-effective and simple Biocompatibility Tunable properties Dual functionality of biomolecules Scalability and broader applications Microorganism-mediated synthesis of copper nanoparticles Mechanism Selection of biological agents for green biosynthesis Characterization of copper nanoparticles Optimization of physico-chemical factors for the biosynthesis of copper nanoparticles Effect of pH Moulai R, Mokhtari H, Gacem M.Ai Biogenic synthesis of nanocopper particles and theirapplicationsTables des matières. Effect of temperature Effect of reaction time Effect of CuSO4 concentration Biological and catalytic activities Antioxidant activity Antitumor activity Antimicrobial activity Antifungal activity Antibacterial activity Antiviral activity Dye removal and environmental remediation Mechanisms of action of copper nanoparticles Generation of reactive oxygen species (ROS) Disruption of cell membranes Interaction with proteins and enzymes DNA and RNA damage Catalytic redox reactions Application in agriculture and insecticidal activity Mode of interaction of copper nanoparticles against insects Nanomaterials as detoxification tools in feeds Detoxification by targeting mycotoxinogenic molds or adsorption of mycotoxins Detoxification of mycotoxins by photocatalysis Experimental Part Material and method Actinomycetes Reactivation of a preserved strain (T003) Purification of the strain Preservation of the purified strain Fungal strains Isolation and preparation of fungal strains Purification of fungal isolates Identification of Fusarium, Rhizoctonia, and Phytophthora Submerged pre-culture of actinomycetes in GYM liquid medium for fermentation preparation I.4. Extraction process of secondary metabolites produced by actinomycetes. I.5. Biosynthesis of copper nanoparticles and characterization I.5.1. Biosynthesis and recovery of copper nanoparticles (CuNPs) from actinomycete culture I.5.2. Characterization of copper nanoparticles (CuNPs) I.6. Measurement of antifungal activity I.6.1. Measurement of antifungal activity of crude extract I.6.2. Measurement of antifungal activity of copper nanoparticles I.7. Antioxidant test by DPPH radical scavenging assay I.8. Evaluation of insecticidal activity I.9. Evaluation of the effect of copper nanoparticles on tomato seed germination and pigment content. I.9.1. Experimental design for germination assay I.9.2. Determination of chlorophyll and photosynthetic pigments in tomato seedlings I.10. Evaluation of the effect of copper nanoparticles on fungal growth and tomato plant health under greenhouse conditions I.10.1. Preparation and transplantation of tomato seedlings for growth experiments I.10.2. Tomato fruit development I.10.3. Fungal inoculation procedure I.10.4. Treatment and comparative evaluation II. Results and discussion II.1. Biogenic Formation of nanostructures mediated by Streptomyces strain Revivification de la souche T003 II.1.1. II.1.2. Fungal strain isolation II.1.2.1. Isolation and identification of Fusarium oxysporum II.1.2.2. Isolation and Identification of Phytophthora infestans II.1.2.3. Isolation and identification of Rhizoctonia solani II.1.3. Biosynthesized copper nanoparticles (CuNPs) Moulai R, Mokhtari H, Gacem M.Aii Biogenic synthesis of nanocopper particles and their applicationsTables des matières. II.1.3.1. Visual observation and initial confirmation of biosynthesized copper nanoparticles (CuNPs) II.1.4. Role of actinomycetes-derived biomolecules in CuNP formation II.1.5. Purification and physical characteristics of the product II.1.5.1. Interpretation of UV–Visible absorbance II.1.5.2. X-ray Diffraction (XRD) analysis II.1.5.3. Analyse par spectroscopie infrarouge à transformée de Fourier (FTIR) II.1.5.4. Scanning Electron Microscopy (SEM) Analysis Discussion Conclusion Biological and agronomic activities of biogenic copper nanoparticles: antifungal, antioxidant, insecticidal, and growth-promoting effects II.2.1. Antifungal effect of CuNPs in PDA medium II.2.2. DPPH radical scavenging assay II.2.3. Insecticidal activity II.2.4. Effect of copper nanoparticles on tomato seed germination and pigment content II.2.5. Effect of copper nanoparticles (CuNPs) on the growth parameters of tomato seedlings after 18 days of cultivation Discussion Conclusion II.3. Preparation and development of tomato plants prior to phytopathogen inoculation and copper nanoparticle treatment II.3.1 Evaluation of the effect of copper nanoparticle (CuNP) treatment on tomato plants infected with Fusarium oxysporum, Rhizoctonia solani, and Phytophthora infestans. II.3.2. Effects of fungal infection on untreated tomato plants II.3.2.1. Tomate infected with Phytophthora infestans II.3.2.2. Tomate infected with Fusarium oxysporum II.3.2.3. Tomate infected with Rhizoctonia solani I.3.3. Effects of chemical pesticide treatment on tomato plants infected with Fusarium oxysporum, Rhizoctonia solani, and Phytophthora infestans. Discussion Conclusion General conclusion References Annexes Moulai R, Mokhtari H, Gacem M.A |
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