Macroalgae Bioplastics: A Sustainable Shift to Mitigate the Ecological Impact of Petroleum-Based Plastics.

The surge in global utilization of petroleum-based plastics, which notably heightened during the COVID-19 pandemic, has substantially increased its harm to ecosystems. Considering the escalating environmental impact, a pivotal shift towards bioplastics usage is imperative. Exploring and implementing bioplastics as a viable alternative could mitigate the ecological burden posed by traditional plastics. Macroalgae is a potential feedstock for the production of bioplastics due to its abundance, fast growth, and high cellulose and sugar content. Researchers have recently explored various methods for extracting and converting macroalgae into bioplastic. Some of the key challenges in the production of macroalgae bioplastics are the high costs of large-scale production and the need to optimize the extraction and conversion processes to obtain high-quality bioplastics. However, the potential benefits of using macroalgae for bioplastic production include reducing plastic waste and greenhouse gas emissions, using healthier materials in various life practices, and developing a promising area for future research and development. Also, bioplastic provides job opportunities in free enterprise and contributes to various applications such as packaging, medical devices, electronics, textiles, and cosmetics. The presented review aims to discuss the problem of petroleum-based plastic, bioplastic extraction from macroalgae, bioplastic properties, biodegradability, its various applications, and its production challenges.

Application of Cystoseira myrica phycosynthesized selenium nanoparticles incorporated with nano-chitosan to control aflatoxigenic fungi in fish feed.

BACKGROUND: The recurrent contaminations of feed materials with mycotoxigenic fungi can endanger both farmed animals and humans. Biosynthesized nanomaterials are assumingly the ideal agents to overcome fungal invasion in feed/foodstuffs, especially when utilizing sustainable sources for synthesis. Herein, the phycosynthesis of selenium nanoparticles (SeNPs) was targeted using Cystoseira myrica algal extract (CE), and the conjugation of CE/SeNPs with chitosan nanoparticles (NCt) to produce potential antifungal nanocomposites for controlling Aspergillus flavus isolates in fish feed. RESULTS: The phycosynthesis of SeNPs with CE was effectually carried out and validated using visible/UV analysis, X-ray diffraction and transmission microscopy; CE/SeNPs had diameters of 8.7 nm and spherical shapes. NCt/CE/SeNPs nanocomposite (173.3 nm mean diameter) was achieved and the component interactions were validated via infrared spectroscopic analysis. The antifungal assessment of screened nanomaterials against three Aspergillus flavus strains indicated that NCt/CE/SeNPs exceeded the fluconazole action using qualitative/quantitative assays. Severe alteration/distortions in A. flavus mycelial structure and morphology were microscopically observed within 48 h of NCt/CE/SeNPs treatment. The treatment of feed ingredients (crushed corn and feed powder) by blending with nanomaterials (NCt, CE/SeNPs and NCt/CE/SeNPs) led to significant reduction in A. flavus count/growth after storage for 7 days; NCt/CE/SeNPs could completely inhibit any fungal growth in feed material. CONCLUSION: The pioneering phycosynthesis of CE/SeNPs and their nanoconjugation with NCt generated bioactive antifungal agents to control A. flavus strains. The innovatively constructed NCt/CE/SeNPs nanocomposite is advised for application as an effectual, biosafe and natural fungicidal conjugate for the protection of fish feed from mycotoxigenic fungi. © 2024 Society of Chemical Industry.

Innovative biosynthesis of silver nanoparticles using yeast glucan nanopolymer and their potentiality as antibacterial composite.

Nanometals (NM) frequently possess potent antimicrobial potentials to combat various pathogens, but their elevated biotoxicity limits their direct applications. The biosynthesis of NM and their capping/conjugation with natural biopolymers can effectually enhance NM stability and diminish such toxicity. Yeast ß-glucan (ßG), from Saccharomyces cerevisiae, was extracted and transformed to nanoparticles (NPs) using alkali/acid facile protocol. The ßG NPs were innovatively employed for direct biosynthesis of silver nanoparticles (Ag NPs) without extra chemical processes. The physicochemical assessments (Fourier-transform infrared, X-ray diffraction, and transmission electron microscopy) validated NPs formation, interaction, and interior capping of Ag NPs in ßG NPs. The synthesized ßG NPs, Ag NPs, and ßG-Ag NPs composite were negatively charged and had minute particle sizes with mean diameters of 58.65, 6.72, and 63.88 nm, respectively. The NPs (plain Ag NPs and composited ßG-Ag NPs) exhibited potent comparable bactericidal actions, opposing Gram+ (Staphylococcus aureus) and Gram- (Escherichia coli, Salmonella Typhimurium, and Pseudomonas aeruginosa). Scanning micrographs, of treated S. aureus and S. Typhimurium with ßG-Ag NPs, elucidated the powerful bactericidal actions of nanocomposite for destructing pathogens' cells. The inventive Ag NPs biosynthesis with ßG NPs and the combined ßG-Ag NPs nanocomposites could be impressively recommended as powerful antibacterial candidates with minor potential toxicity.

Application of ZnO Nanoparticles Phycosynthesized with Ulva fasciata Extract for Preserving Peeled Shrimp Quality.

Zinc oxide nanoparticles (ZnONPs) were the targets of numerous biological syntheses to attain their precious values in various biomedical fields. The phycosynthesis of ZnONPs were innovatively investigated using cell-free extract of the macroalgae, Ulva fasciata Delile. The phycosynthesized U. fasciata-zinc oxide nanoparticles (UFD-ZnONPs) had 77.81 nm mean size, with flower and sphere shapes and positive zeta potential. The UFD-ZnONPs infra-red analysis indicated their basic components' cross-linkage. The antibacterial potentialities of UFD-ZnONPs were confirmed, qualitatively and quantitatively, against foodborne microorganisms (Escherichia coli plus Staphylococcus aureus); the bactericidal action was higher for UFD-ZnONPs than the annealed phycosynthesized ZnONPs. The scanning micrographs of S. aureus and E. coli cells treated with UFD-ZnONPs indicated the severe action of nanoparticles to destroy bacterial cells in time-dependent manners. Peeled shrimps (Fenneropenaeus indicus) were biopreservated through refrigerated storage (4 °C) with UFD-ZnONPs based solution for six days. The microbial examination of UFD-ZnONPs -treated shrimps displayed decrease in microbial loads throughout the storage days. Moreover, the UFD-ZnONPs-treated shrimps showed acceptable sensorial attributes (appearance, odor, color and texture) compared to untreated shrimps. UFD-ZnONPs nanocomposite concentration of 3% and 5% could be remarkably suggested as efficient procedure for shrimps' biopreservation during refrigerated storage regarding sensorial quality and microbial profile of product.

Application of Quercus infectoria extract as a natural antimicrobial agent for chicken egg decontamination / Aplicación de un extracto de Quercus infectoria como agente antimicrobiano natural para la desinfección de huevos de gallina

Egg contamination with microbial pathogens is an enduring worldwide concern. Natural products are frequently recommended as ideal alternatives to substitute synthetic and chemical antimicrobials. Oak galls (Quercus infectoria) are aberrant growths on oak trees that have many medicinal and pharmaceutical applications. Q. infectoria extract (QIE) antimicrobial action was assessed against many microbial species, and used for eggshell decontamination. QIE antimicrobial activity was evidenced against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium and Candida albicans, using different assay methods. Disinfection of eggshell microbial contamination, by immersion in 1% QIE solution, sharply reduced total colony count, yeasts and molds, Enterobacteriaceae. E. coli and S. aureus were completely inhibited after 60min of immersion in QIE. QIE biochemical analysis revealed elevated contents of phenolic and flavonoid compounds. The captured micrographs of S. aureus cells treated with QIE showed strong alterations in cell morphology; cells were entirely lysed and ruptured after 6h of treatment. QIE can be recommended as an effective and natural disinfectant for decontaminating eggshells from pathogenic microorganisms.

La contaminación de huevos con patógenos microbianos es un problema constante en todo el mundo. Con frecuencia se recomiendan diversos productos naturales como alternativas ideales para sustituir a los antimicrobianos sintéticos. Las agallas de roble (Quercus infectoria) son de crecimiento aberrante en los robles y tienen muchas aplicaciones medicinales y farmacéuticas. Se evaluó la acción antimicrobiana del extracto de Quercus infectoria (QIE) contra varias especies microbianas y también este se aplicó para la descontaminación de cáscaras de huevo. La actividad antimicrobiana del extracto de QIE se evidenció en relación con Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium y Candida albicans, utilizando diferentes métodos de ensayo. La inmersión de las cáscaras de huevo en extracto de QIE al 1% logró una fuerte reducción del recuento total de colonias, de levaduras y de mohos, y de miembros de Enterobacteriaceae. La inmersión durante 60 min inhibió completamente el desarrollo de E. coli y S. aureus. El análisis bioquímico del extracto de QIE reveló que este tiene un contenido elevado de compuestos fenólicos y de flavonoides. Se documentó mediante micrografías la presencia de grandes alteraciones en la morfología celular de S. aureus tras la exposición al extracto de QIE: las células se lisaron completamente y se rompieron después de 6h de tratamiento. El extracto de QIE se puede recomendar como un desinfectante eficaz y natural para descontaminar cáscaras de huevos de microorganismos patógenos.

Soil emendation with nano-fungal chitosan for heavy metals biosorption.

The bioremediation of water and soil, from heavy metal (HM) contamination, is a continuing worldwide demand. Chitosan, as a promising bioactive polymer, was produced from grown fungal (Cunninghamella elegans) mycelia and had a molecular weight of 112 kDa and a deacetylation degree of 87%. Sodium tripolyphosphate was applied for the synthesis of chitosan nanoparticles (NCt) from fungal chitosan (Cts); the particle size of produced NCt was in range of 5-45 nm. The produced biopolymers were used for HM absorption, Pb2+ and Cu2+ at concentration range of 100-300 ppm, from aqueous solution and soil matrix. Both Cts and NCt had high adsorption capacity toward the examined HM, with higher affinity as adsorbents to Pb2+ than to adsorb Cu2+ from water or after amendment of soil matrix. The produced NCt particles were highly effective than bulk Cts for the remediation and biosorption of contaminant metals, Pb2+ and Cu2+. Both Cts and NCt could be effectually applied as amendments in HM-contaminated soils for their bioremediation.

Skin protectant textiles loaded with fish collagen, chitosan and oak galls extract composite.

Skin protection and control of its microbial pathogens are highly important demands; natural biological agents are the ideals for that. Collagen (Cg) was extracted and characterized from skin and scales of Nile tilapia fish (Oreochromis niloticus), chitosan (Cts) was extracted from shrimp shells and extract of oak (Quercus infectoria) galls (OGE) was prepared. The antimicrobial potentialities of extracted agents, Cts and OGE, were qualitatively proved against skin pathogens, Staphylococcus aureus and Candida albicans, including both antibiotic sensitive and resistant strains, neither Cg nor negative control exhibited antimicrobial actions toward examined strain. The entire agents were loaded onto cotton fabrics and evaluated for antimicrobial actions and durability. Loaded textiles with the combined extracts' composite were the most effectual followed by individual treatments with OGE and Cts, respectively. Treated textiles upheld most of their antimicrobial activity after 2 laundering cycles toward all microbial pathogens. This invention could be consequently applied for production of skin protectant and hygienic fabrics.

Application of Quercus infectoria extract as a natural antimicrobial agent for chicken egg decontamination.

Egg contamination with microbial pathogens is an enduring worldwide concern. Natural products are frequently recommended as ideal alternatives to substitute synthetic and chemical antimicrobials. Oak galls (Quercus infectoria) are aberrant growths on oak trees that have many medicinal and pharmaceutical applications. Q. infectoria extract (QIE) antimicrobial action was assessed against many microbial species, and used for eggshell decontamination. QIE antimicrobial activity was evidenced against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium and Candida albicans, using different assay methods. Disinfection of eggshell microbial contamination, by immersion in 1% QIE solution, sharply reduced total colony count, yeasts and molds, Enterobacteriaceae. E. coli and S. aureus were completely inhibited after 60min of immersion in QIE. QIE biochemical analysis revealed elevated contents of phenolic and flavonoid compounds. The captured micrographs of S. aureus cells treated with QIE showed strong alterations in cell morphology; cells were entirely lysed and ruptured after 6h of treatment. QIE can be recommended as an effective and natural disinfectant for decontaminating eggshells from pathogenic microorganisms.

Fungal chitosan and Lycium barbarum extract as anti-Listeria and quality preservatives in minced catfish.

Listeria monocytogenes is a foodborne bacterial pathogen that causes serious health risks. Chitosan (Ch) is a bioactive polymer that could be effectively applied for foodstuffs biopreservation. Lycium barbarum (Goji berry) is ethnopharmaceutical fruit that have diverse health protecting benefits. Chitosan was produced from A. niger and employed with L. barbarum extract (LBE) as blends for Listeria control and quality biopreservation of African catfish mince (Clarias gariepinus). Chitosan could utterly control L. monocytogenes survival in fish mince and its efficacy was strengthened with added LBE at 0.2 and 0.4%. Blending of fish mince with Ch could effectively reduce the progress of chemical spoilage parameters and this protective effect was greatly enhanced with increased addition of LBE. The sensorial assessment of treated minces indicated panelists preferences for the entire attributes of blended samples with Ch and LBE, particularly with storage prolongation. Scanning micrographs elucidated the antibacterial action of Ch against L. monocytogenes. Results recommended the application of fungal Ch/LBE composites as biopreservatives and anti-listerial agents, through their blending with catfish mince, to eliminate bacterial growth, enhance sensory and storage attributes of preserved fish.

Application of fungal chitosan incorporated with pomegranate peel extract as edible coating for microbiological, chemical and sensorial quality enhancement of Nile tilapia fillets.

Fish are generous sources for providing man with his essential nutritional requirements, but the extreme susceptibility to quality deterioration hinders their optimal usage and storage. Natural derivatives are always the perfect alternatives for food preservation. The application of fungal chitosan (Ch), from Aspergillus niger, and pomegranate peel extract (PPE), in coating films for Nile tilapia (Oreochromis niloticus) fillets preservation and maintaining their microbiological, chemical and sensorial quality during cooled storage at 4°C for 30days, was investigated. Fish fillet were coated with Ch (2%) and combined Ch+PPE, at PPE percentages of 0.5, 1.0, 1.5 and 2.0%. Fillets coating resulted in sharp decrease of the entire microbial counts during storage; the increased concentrations from PPE strengthened coating film antimicrobial activity. Additionally, fillets coating could retard the chemical spoilage parameters increasing, i.e. nitrogen volatile base (TVB-N), peroxide value (PV) and reactive substances of thiobarbituric acid (TBARS), during storage period. The sensory evaluation indicated higher preferences for the odor, texture, color and overall quality of coated samples. Fish fillets coating with Ch and Ch+PPE could be recommended for shelf life extension and maintaining the microbiological, chemical and sensorial quality through the application of safe preservatives from natural origins.

Control of citrus molds using bioactive coatings incorporated with fungal chitosan/plant extracts composite.

BACKGROUND: The ongoing postharvest loss in citrus fruits, due to fungal infection, is a chronic economic and agricultural problem. Most of citrus damage is caused by Penicillium spp., e.g. green mold (P. digitatum) and blue mold (P. italicum). Fungal chitosan, from Mucor rouxii, and plant extracts from cress seeds, olive leaves, pomegranate peels and senna pods, were evaluated as antifungal agents against the phytopathogenic fungi, P. digitatum and P. italicum, using in vitro qualitative and quantitative assays. RESULTS: All natural agents tested exhibited potent antifungal activity; the most powerful agent was cress (Lepidium sativum) seed extract, followed by pomegranate (Punica granatum) peel extract. Fungal chitosan also had a remarkable fungicidal potentiality using both evaluation assays. Penicillium digitatum was generally more resistant than P. italicum toward all examined agents. The incorporation of each individual natural agent in coating material resulted in a great reduction in fungal growth and viability. The addition of chitosan combined with cress and pomegranate extracts, to the coating materials, prevented coated citrus fruit from decay by green and blue mold for a 2-week storage period. CONCLUSION: Natural derivatives could be recommended as powerful antifungal alternatives to protect citrus fruits from postharvest fungal decay.

Production of fungal chitosan from date wastes and its application as a biopreservative for minced meat.

Raw and processed meat contaminated with pathogenic microorganisms is a continuing worldwide problem facing health and industry overseers. Fungal chitosan was extracted, purified and characterized from Aspergillus brasiliensis (niger) ATCC 16404 grown in date syrup (dips) and applied as a potential meat biopreservative. The main features of produced chitosan were a deacetylation degree of 81.3%, a molecular weight of 31,000Da, 96% solubility in 1% acetic acid solution and a harmonized IR-spectrum to standard commercial chitosan. The application of fungal chitosan, as a natural and safe biopreservative for minced meat, was conducted in comparison with potassium sorbate, as a commercial meat preservative. Treated meat samples with 0.02% chitosan was the least trials in microbial contents, i.e. total count, coliforms, ß-glucuronidase-positive Escherichia coli, Enterobacteriaceae, yeasts and molds, Staphylococcus aureus and coagulase positive staphylococci. The antimicrobial activity of fungal chitosan was considerably greater than that of potassium sorbate or their combination at 0.01% from each. Sensory characteristics, e.g. color, odor and texture, of treated meat with chitosan, were higher than those of control and potassium sorbate treated samples. Fungal chitosan, however, could be recommended as a powerful, natural and eco-friendly alternative for meat preservation and overall quality maintenance.

Botryticidal activity of nanosized silver-chitosan composite and its application for the control of gray mold in strawberry.

Botrytis cinerea Pers, the gray mold fungus, is among the most dangerous plant pathogens that cause great losses in agricultural crops. The botryticidal activities of nanosized silver (nano Ag), fungal chitosan (CTS) irradiated fungal chitosan (IrCTS), and nano Ag-IrCTS composite were investigated. All of the examined materials exhibited powerful antifungal activity against B. cinerea. The most effective compound was nano Ag-IrCTS composite with a minimal inhibitory concentration of 125 µg/mL. The microscopic examination, of treated B. cinerea with the composite, revealed that an obvious alteration in mycelial shape was appeared accompanied and moderate lysis in fungal hyphae. With the prolongation of treatment, most of the fungal mycelia were lysed into small and elastic fragments. The consequence of strawberries coating, with antifungal composite based solution, was the disappearance of gray mold infection signs in 90% of the contaminated fruits after 7 d of storage, treated fruits had a fresh-like appearance at the end of storage. Coating with nano Ag-IrCTS solution could be highly recommended regarding its efficiency in prohibiting B. cinerea growth, preventing gray mold decay and enhancing the overall quality of coated strawberry fruits.

Antifungal action of Pichia anomala against aflatoxigenic Aspergillus flavus and its application as a feed supplement.

BACKGROUND: The disastrous problem of animal feed contamination by mycotoxigenic fungi continues to challenge researchers and health overseers worldwide. With the aim of preventing Aspergillus flavus growth in vitro and in corn feed, the yeast Pichia anomala was examined as a biocontrol agent. RESULTS: The yeast strain could efficiently prohibit the growth of A. flavus. P. anomala was able to produce exo-chitinase and ß-1,3-glucanase which could be suggested as a mode of action for its antifungal activity. Scanning electron microscopy of cultured P. anomala with fungal hypha revealed that A. flavus was colonised by the biocontrol yeast which subsequently led to complete hyphal lysis and deterioration. The supplementation with of P. anomala cells, as a protein source, led to an obvious increase in animals' weight gain and protein content in feed grain. Moreover, after consumption of P. anomala-supplemented feed, there was a remarkable decrease in the mortality rate among fed animals. CONCLUSION: P. anomala could be strongly recommended as a biocontrol agent against A. flavus which contaminates animal feed. Furthermore, the application of yeast cells, as a feed additive, proved its efficiency for escalating protein content and enhancing animal performance.

Evaluation of fungal chitosan as a biocontrol and antibacterial agent using fluorescence-labeling.

Chitosan is a precious biological polysaccharide that could be applied in several fields. Fluorescein isothiocyanate-labeled chitosan (FITC-CTS) was synthesized as a macromolecular fluorophore added to fungal chitosan from Aspergillus niger, to investigate the interaction mechanism and antibacterial performance of (FITC-CTS) against Escherichia coli and Micrococcus leteus. Fluorescence imaging was used to demonstrate chitosan effect on the bacterial cells. Fluorescence density of treated bacteria with FITC-CTS was correlated with viable cell number. Electron micrographs of treated E. coli with fungal chitosan revealed that chitosan principally interact with bacterial cell wall, causing cell wall lyses with exposure time prolongation. Fungal chitosan could be proposed for bacterial growth control as a powerful, natural and safe alternative to synthetic and chemical bactericides. Fluorescence labeling proved to be an efficient tool for determining the antimicrobial activity of chitosan.

Surface decontamination and quality enhancement in meat steaks using plant extracts as natural biopreservatives.

Nine plant extracts were evaluated as biopreservatives to decontaminate and maintain the quality of meat steaks. Most of the extracts exhibited a remarkable antibacterial activity against antibiotic resistant strains from Salmonella Typhimurium and Staphylococcus aureus. The pomegranate peel extract (PPE), cinnamon bark extract (CBE), and lemon grass leaves extract (LGE) were the most effective as bactericides, with minimal inhibitory concentrations (MIC) of 250, 350, and 550 µg/mL, respectively. The most effective treatments, for decontaminating meat steak surfaces, were the application of combined PPE, CBE, and LGE at their MIC values and the treatment with double MIC from PPE; these treatments resulted in complete bacterial inhibitions during the first 2 days of storage period for 7 days. The sensory evaluation of treated steaks revealed that these two treatments had the highest panelist overall scores. The highest scores, for individual attributes, were observed in the treated steaks with double MIC from PPE. Application of plant extracts could be impressively recommended for comprehensive meat decontamination and quality attributes enhancement.

Antimicrobial textile treated with chitosan from Aspergillus niger mycelial waste.

The waste biomass of Aspergillus niger, following citric acid production, was used as a source for fungal chitosan extraction. The produced chitosan was characterized with deacetylation degree of 89.6%, a molecular weight of 25,000 dalton, 97% solubility in 1% acetic acid solution and comparable FT-IR spectra to standard shrimp chitosan. Fungal chitosan was applied as a cotton fabric finishing agent using pad-dry-cure method. The topographical structure of chitosan-treated fabrics (CTF) was much improved compared with control fabrics. CTF, after durability tests, exhibited a powerful antimicrobial activity against both E. coli and Candida albicans, the captured micrographs for E. coli cells contacted with CTF showed a complete lysis of cell walls with the prolonging contact time. The produced antimicrobial CTF could be proposed as a suitable material for many medical and hygienic applications.