Biosynthesis of zinc oxide nanoparticles with antimicrobial, anticancer, antioxidant and photocatalytic activities by the endophytic Alternaria tenuissima

Novel nanoconjugates of metal oxides and natural red pigment from the endophyte Monascus ruber using solid-state fermentation

BACKGROUND

Antimicrobial resistance has emerged as a major global health threat, necessitating the urgent development of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes. With this view, we developed three novel nanoconjugates using microbial natural pigment for effective application against certain pathogenic microbes.

RESULTS

A natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized by different techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated. Moreover, the antibiofilm, protein leakage, growth curve, and UV light irradiation effect of the synthesized nanoconjugates were also studied. Our results confirmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO, RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fungal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO against the tested microbes. The highest % inhibition of biofilm formation by the RP-ZnO nanoconjugate. Membrane leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more effective than RP-MgO and RP-CuO nanoconjugates. Finally, UV light irradiation intensified the antibiotic action of the three nanoconjugates and RP-ZnO potential was greater than that of the RP-MgO, and RP-CuO nanoconjugates.

CONCLUSION

These findings pave the way for exploiting the synthesized nanoconjugates as potential materials in biomedical applications, promoting natural, green, and eco-friendly approaches.

Harnessing biological synthesis: Zinc oxide nanoparticles for plant biotic stress management

Crop growth and yield are negatively impacted by increased biotic stress in the agricultural sector due to increasing global warming and changing climatic patterns. The host plant's machinery is exploited by biotic stress, which is caused by organisms like bacteria, fungi, viruses, insects, nematodes, and mites. This results in nutrient deprivation, increased reactive oxygen species and disturbances in physiological, morphological, and molecular processes. Although used widely, conventional disease management strategies like breeding, intercropping, and chemical fertilizers have drawbacks in terms of time commitment and environmental impact. An environmentally beneficial substitute is offered by the developing field of nanotechnology, where nanoparticles such as zinc oxide are gaining popularity due to their potential applications as antimicrobials and nano-fertilizers. This review delves into the biological synthesis of ZnO nanoparticles employing plants and microbes, function of ZnO nanoparticles in biotic stress mitigation, elucidating their effectiveness and toxicological implications in agricultural. This study supports a cautious approach, stressing the prudent application of ZnO nanoparticles to avoid possible toxicity, in line with the larger global agenda to end hunger, guarantee food security, and advance sustainable agriculture.

Bioprospecting endophytic fungi for bioactive metabolites with seed germination promoting potentials

There is an urgent need for new bioactive molecules with unique mechanisms of action and chemistry to address the issue of incorrect use of chemical fertilizers and pesticides, which hurts both the environment and the health of humans. In light of this, research was done for this work to isolate, identify, and evaluate the germination-promoting potential of various plant species' fungal endophytes. Zea mays L. (maize) seed germination was examined using spore suspension of 75 different endophytic strains that were identified. Three promising strains were identified through screening to possess the ability mentioned above. These strains Alternaria alternate, Aspergilus flavus, and Aspergillus terreus were isolated from the stem of Tecoma stans, Delonix regia, and Ricinus communis, respectively. The ability of the three endophytic fungal strains to produce siderophore and indole acetic acid (IAA) was also examined. Compared to both Aspergillus flavus as well as Aspergillus terreus, Alternaria alternata recorded the greatest rates of IAA, according to the data that was gathered. On CAS agar versus blue media, all three strains failed to produce siderophores. Moreover, the antioxidant and antifungal potentials of extracts from these fungi were tested against different plant pathogens. The obtained results indicated the antioxidant and antifungal activities of the three fungal strains. GC-Mass studies were carried out to determine the principal components in extracts of all three strains of fungi. The three strains' fungus extracts included both well-known and previously unidentified bioactive compounds. These results may aid in the development of novel plant growth promoters by suggesting three different fungal strains as sources of compounds that may improve seed germination. According to the study that has been given, as unexplored sources of bioactive compounds, fungal endophytes have great potential.

Effect of Zinc Oxide Nanoparticles as Feed Additive on Blood Indices, Physiological, Immunological Responses, and Histological Changes in Broiler Chicks

A feeding trial of 5-week duration was performed to assess the response of broiler chicks to dietary supplementation with different doses of myco-fabricated zinc oxide nanoparticles (ZONPs) on blood indices, physiological, immunological response, antioxidant status, intestinal microbial count, and histological changes in immune organs. A total of 162 3-day-old Ross 308 broiler chicks were weighed individually and distributed equally into 3 dietary treatments with 6 replicate of 9 chicks in each in a completely randomized design. Chicks were fed ad libitum a basal ration prepared as starter, grower, and finisher supplemented with 0 (T1, control), 40 (T2), and 60 (T3) mg zinc oxide nanoparticles (ZONPs)/kg feed. Results showed that supplementing with ZONPs at both studied levels increased the relative weights of the spleen, bursa, thymus, and liver and decreased the relative weight of the kidney, gizzard, and intestine. A significant increase in the concentrations of hemoglobin (Hb), hematocrit (PCV%), red and white blood cell counts, total protein (TP), globulin (GLOB), aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), superoxide dismutase (SOD), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) and a significant decrease in malonaldehyde (MDA), uric acid, and creatinine concentration were observed. Furthermore, all immunological organs showed histological alteration and increased both types of immunity in ZONPs groups with more pronounced effects in the T2 group.

Nanoparticles and Chemical Inducers: A Sustainable Shield against Onion White Rot

This study investigated the effectiveness of nanoparticles and chemical inducers in managing onion white rot caused by Sclerotium cepivorum. The pathogen severely threatens onion cultivation, resulting in significant yield losses and economic setbacks. Traditional fungicides, though effective, raise environmental concerns, prompting a shift toward eco-friendly alternatives. In this study, four S. cepivorum isolates were utilized, each exhibiting varying degrees of pathogenicity, with the third isolate from Abu-Hamad demonstrating the highest potency. During the in vitro studies, three nanoparticles (NPs) were investigated, including Fe3O4 NPs, Cu NPs, and ZnO NPs, which demonstrated the potential to inhibit mycelial growth, with salicylic acid and Fe3O4 NPs exhibiting synergistic effects. In vivo, these nanoparticles reduced the disease incidence and severity, with Fe3O4 NPs at 1000-1400 ppm resulting in 65.0-80.0% incidence and 80.0-90.0% severity. ZnO NPs had the most positive impact on the chlorophyll content, while Cu NPs had minimal effects. At 1000 ppm, Fe3O4 NPs had variable effects on the phenolic compounds (total: 6.28, free: 4.81, related: 2.59), while ZnO NPs caused minor fluctuations (total: 3.60, free: 1.82, related: 1.73). For the chemical inducers, salicylic acid reduced the disease (10.0% incidence, 25.0% to 10.0% severity) and promoted growth, and it elevated the chlorophyll values and enhanced the phenolic compounds in infected onions. Potassium phosphate dibasic (PDP) had mixed effects, and ascorbic acid showed limited efficacy toward disease reduction. However, PDP at 1400 ppm and ascorbic acid at 1000 ppm elevated the chlorophyll values and enhanced the phenolic compounds. Furthermore, this study extended to traditional fungicides, highlighting their inhibitory effects on S. cepivorum. This research provides a comprehensive comparative analysis of these approaches, emphasizing their potential in eco-friendly onion white rot management.

Myco-fabricated ZnO nanoparticles ameliorate neurotoxicity in mice model of Alzheimer's disease via acetylcholinesterase inhibition and oxidative stress reduction

Alzheimer's disease (AD) is one of the primary health problems linked to the decrease of acetylcholine in cholinergic neurons and elevation in oxidative stress. Myco-fabrication of ZnO-NPs revealed excellent biological activities, including anti-inflammatory and acetylcholinesterase inhibitory potentials. This study aims to determine if two distinct doses of myco-fabricated ZnO-NPs have a positive impact on behavioral impairment and several biochemical markers associated with inflammation and oxidative stress in mice that have been treated by aluminum chloride (AlCl3) to induce AD. Sixty male mice were haphazardly separated into equally six groups. Group 1 was injected i.p. with 0.5 ml of deionized water daily during the experiment. Mice in group 2 received AlCl3 (50 mg/kg/day i.p.). Groups 3 and 4 were treated i.p. with 5 and 10 mg/kg/day of ZnO-NPs only, respectively. Groups 5 and 6 were given i.p. 5 and 10 mg/kg/day ZnO-NPs, respectively, add to 50 mg/kg/day AlCl3. Results showed that the AlCl3 caused an increase in the escape latency time and a reduction in the time spent in the target quadrant, indicating a decreased improvement in learning and memory. Moreover, acetylcholinesterase enzyme (AChE) activity and malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and interleukin 1β (IL-1β) levels were significantly increased, and the content of glutathione (GSH), activities of superoxide dismutase (SOD), catalase (CAT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), as well as levels of serotonin and dopamine, were decreased in brain tissues only in AlCl3 treated mice. However, treatment of mice with myco-fabrication of ZnO-NPs at doses of 5 or 10 mg/kg improves learning and memory function through ameliorate all the previous parameters in the AD mice group. The low dose of 5 mg/kg is more effective than a high dose of 10 mg/kg. In accordance with these findings, myco-fabricated ZnO-NPs could enhance memory and exhibit a protective influence against memory loss caused by AlCl3.

Bioactive ZnO Nanoparticles: Biosynthesis, Characterization and Potential Antimicrobial Applications

In recent years, biosynthesized zinc oxide nanoparticles (ZnONPs) have gained tremendous attention because of their safe and non-toxic nature and distinctive biomedical applications. A diverse range of microbes (bacteria, fungi and yeast) and various parts (leaf, root, fruit, flower, peel, stem, etc.) of plants have been exploited for the facile, rapid, cost-effective and non-toxic synthesis of ZnONPs. Plant extracts, microbial biomass or culture supernatant contain various biomolecules including enzymes, amino acids, proteins, vitamins, alkaloids, flavonoids, etc., which serve as reducing, capping and stabilizing agents during the biosynthesis of ZnONPs. The biosynthesized ZnONPs are generally characterized using UV-VIS spectroscopy, TEM, SEM, EDX, XRD, FTIR, etc. Antibiotic resistance is a serious problem for global public health. Due to mutation, shifting environmental circumstances and excessive drug use, the number of multidrug-resistant pathogenic microbes is continuously rising. To solve this issue, novel, safe and effective antimicrobial agents are needed urgently. Biosynthesized ZnONPs could be novel and effective antimicrobial agents because of their safe and non-toxic nature and powerful antimicrobial characteristics. It is proven that biosynthesized ZnONPs have strong antimicrobial activity against various pathogenic microorganisms including multidrug-resistant bacteria. The possible antimicrobial mechanisms of ZnONPs are the generation of reactive oxygen species, physical interactions, disruption of the cell walls and cell membranes, damage to DNA, enzyme inactivation, protein denaturation, ribosomal destabilization and mitochondrial dysfunction. In this review, the biosynthesis of ZnONPs using microbes and plants and their characterization have been reviewed comprehensively. Also, the antimicrobial applications and mechanisms of biosynthesized ZnONPs against various pathogenic microorganisms have been highlighted.

Green Synthesis of Metal and Metal Oxide Nanoparticles: A Review of the Principles and Biomedical Applications

In recent years, interest in nanotechnology has increased exponentially due to enhanced progress and technological innovation. In tissue engineering, the development of metallic nanoparticles has been amplified, especially due to their antibacterial properties. Another important characteristic of metal NPs is that they enable high control over the features of the developed scaffolds (optimizing their mechanical strength and offering the controlled release of bioactive agents). Currently, the main concern related to the method of synthesis of metal oxide NPs is the environmental impact. The physical and chemical synthesis uses toxic agents that could generate hazards or exert carcinogenicity/environmental toxicity. Therefore, a greener, cleaner, and more reliable approach is needed. Green synthetic has come as a solution to counter the aforementioned limitations. Nowadays, green synthesis is preferred because it leads to the prevention/minimization of waste, the reduction of derivatives/pollution, and the use of non-toxic (safer) solvents. This method not only uses biomass sources as reducing agents for metal salts. The biomolecules also cover the synthesized NPs or act as in situ capping and reducing agents. Further, their involvement in the formation process reduces toxicity, prevents nanoparticle agglomeration, and improves the antimicrobial activity of the nanomaterial, leading to a possible synergistic effect. This study aims to provide a comprehensive review of the green synthesis of metal and metal oxide nanoparticles, from the synthesis routes, selected solvents, and parameters to their latest application in the biomedical field.

Zinc oxide nanoparticles prepared through microbial mediated synthesis for therapeutic applications: a possible alternative for plants

Zinc oxide nanoparticles (ZnO-NPs) synthesized through biogenic methods have gained significant attention due to their unique properties and potential applications in various biological fields. Unlike chemical and physical approaches that may lead to environmental pollution, biogenic synthesis offers a greener alternative, minimizing hazardous environmental impacts. During biogenic synthesis, metabolites present in the biotic sources (like plants and microbes) serve as bio-reductants and bio-stabilizers. Among the biotic sources, microbes have emerged as a promising option for ZnO-NPs synthesis due to their numerous advantages, such as being environmentally friendly, non-toxic, biodegradable, and biocompatible. Various microbes like bacteria, actinomycetes, fungi, and yeast can be employed to synthesize ZnO-NPs. The synthesis can occur either intracellularly, within the microbial cells, or extracellularly, using proteins, enzymes, and other biomolecules secreted by the microbes. The main key advantage of biogenic synthesis is manipulating the reaction conditions to optimize the preferred shape and size of the ZnO-NPs. This control over the synthesis process allows tailoring the NPs for specific applications in various fields, including medicine, agriculture, environmental remediation, and more. Some potential applications include drug delivery systems, antibacterial agents, bioimaging, biosensors, and nano-fertilizers for improved crop growth. While the green synthesis of ZnO-NPs through microbes offers numerous benefits, it is essential to assess their toxicological effects, a critical aspect that requires thorough investigation to ensure their safe use in various applications. Overall, the presented review highlights the mechanism of biogenic synthesis of ZnO-NPs using microbes and their exploration of potential applications while emphasizing the importance of studying their toxicological effects to ensure a viable and environmentally friendly green strategy.

Gamma rays-assisted bacterial synthesis of bimetallic silver-selenium nanoparticles: powerful antimicrobial, antibiofilm, antioxidant, and photocatalytic activities

BACKGROUND

Bimetallic nanoparticles (BNPs) has drawn a lot of attention especially during the last couple of decades. A bimetallic nanoparticle stands for a combination of two different metals that exhibit several new and improved physicochemical properties. Therefore, the green synthesis and design of bimetallic nanoparticles is a field worth exploring.

METHODS

In this study, we present a green synthesis of silver nanoparticles (Ag NPs), selenium (Se) NPs, and bimetallic Ag-Se NPs using Gamma irradiation and utilizing a bacterial filtrate of Bacillus paramycoides. Different Techniques such as UV-Vis., XRD, DLS, SEM, EDX, and HR-TEM, were employed for identifying the synthesized NPs. The antimicrobial and antibiofilm activities of both the Ag/Se monometallic and bimetallic Ag-Se NPs were evaluated against some standard microbial strains including, Aspergillus brasiliensis ATCC16404, Candida albicans ATCC10231, Alternaria alternate EUM108, Fusarium oxysporum EUM37, Escherichia coli ATCC11229, Bacillus cereus ATCC15442, Klebsiella pneumoniae ATCC13883, Bacillus subtilis ATCC15442, and Pseudomonas aeruginosa ATCC6538 as a model tested pathogenic microbes. The individual free radical scavenging potentials of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs were determined using the DPPH radical scavenging assay. The degradation of methylene blue (MB) dye in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was used to assess their photocatalytic behavior.

RESULTS

According to the UV-Vis. spectrophotometer, the dose of 20.0 kGy that results in Ag NPs with the highest O.D. = 3.19 at 390 nm is the most effective dose. In a similar vein, the optimal dose for the synthesis of Se NPs was 15.0 kGy dose with O.D. = 1.74 at 460 nm. With a high O.D. of 2.79 at 395 nm, the most potent dose for the formation of bimetallic Ag-Se NPs is 15.0 kGy. The recorded MIC-values for Ag-Se NPs were 62.5 µg mL- 1, and the data clearly demonstrated that C. albicans was the organism that was most susceptible to the three types of NPs. The MIC value was 125 µg mL- 1 for both Ag NPs and Se NPs. In antibiofilm assay, 5 µg mL- 1 Ag-Se NPs inhibited C. albicans with a percentage of 90.88%, E. coli with a percentage of 90.70%, and S. aureus with a percentage of 90.62%. The synthesized NPs can be arranged as follows in decreasing order of antioxidant capacity as an antioxidant result: Ag-Se NPs > Se NPs > Ag NPs. The MB dye degradation in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was confirmed by the decrease in the measured absorbance (at 664 nm) after 20 min of exposure to sunlight.

CONCLUSION

Our study provides insight towards the synthesis of bimetallic NPs through green methodologies, to develop synergistic combinatorial antimicrobials with possible applications in the treatment of infectious diseases caused by clinically and industrial relevant drug-resistant strains.

Fungi-mediated synthesis of nanoparticles: characterization process and agricultural applications

In the field of nanotechnology, the use of biologically active products from fungi for the reduction and synthesis of nanoparticles as an alternative to toxic chemicals has received extensive attention, due to their production of large quantities of proteins, high yields, easy handling, and the low toxicity of the residues. Fungi have become valuable tools for the manufacture of nanoparticles in comparison with other biological systems because of their enhanced growth control and diversity of metabolites, including enzymes, proteins, peptides, polysaccharides, and other macro-molecules. The ability to use different species of fungi and to perform the synthesis under different conditions enables the production of nanoparticles with different physicochemical characteristics. Fungal nanotechnology has been used to develop and offer products and services in the agricultural, medicinal, and industrial sectors. Agriculturally, it has found applications in plant disease management, crop improvement, biosensing, and the production of environmentally friendly, non-toxic pesticides and fertilizers to enhance agricultural production in general. The subject of this review is the application of fungi in the synthesis of inorganic nanoparticles, characterization, and possible applications of fungal nanoparticles in the diverse agricultural sector. The literature shows potential uses of fungi in biogenic synthesis, enabling the production of nanoparticles with different physiognomies. © 2023 Society of Chemical Industry.

Visualization of the relationship between fungi and cancer from the perspective of bibliometric analysis

The relationship between cancer and microorganisms has been extensively studied, with bacteria receiving more attention than fungi. However, fungi have been shown to play a significant role in cancer development and progression. Understanding the underlying mechanisms is crucial for identifying new avenues in prevention and treatment. To evaluate the current state of research on fungi and cancer, we conducted a comprehensive bibliometric analysis. Using the Web of Science Core Collection database, we searched for English-language articles published between 1998 and 2022. Analyzing the resulting publication data, we identified trends, patterns, and research gaps. Our analysis encompassed co-authorship networks, citation analysis, and keyword co-occurrence analysis. With 8283 publications identified, averaging 331.32 publications per year, our findings highlight China, the United States, India, Japan, and Germany as the top contributing countries. The Chinese Academy of Sciences, Sun Yat-Sen University, and University of São Paulo emerged as the most productive institutions. Key themes in the literature included "cancer," "cytotoxicity," "apoptosis," "metabolites," and "fungus." Recent trends indicate increased interest in keywords such as "green synthesis," "molecular docking," "anticancer activity," "antibacterial," "anticancer," and "silver nanoparticles." Our study provides a comprehensive assessment of the current research landscape in the field of fungi and cancer, offering insights into collaborative networks, research directions, and emerging hotspots. The growing publication rate demonstrates the rising interest in the topic, while identifying leading countries, institutions, and research themes serves as a valuable resource for researchers, policymakers, and funders interested in supporting investigations on fungi-derived compounds as potential anti-cancer agents.

Bifunctional role of some biogenic nanoparticles in controlling wilt disease and promoting growth of common bean

In the present era, nanomaterials are emerging as a powerful tool for management of plant disease and improving crop production to meet the growing global need for food. Thus, this paper was conducted to explore the effectiveness of five different types of nanoparticles (NPs) viz., Co₃O₄NPs, CuONPs, Fe₃O₄NPs, NiONPs, and ZnONPs as treatments for Fusarium wilt as well as their role in promoting growth of the common bean plant. The five types of NPs were applied as a treatment for wilt in two ways, therapeutic and protective plans under greenhouse conditions. In vivo experiments showed that all types of NPs significantly increased disease control and diminished the symptoms of Fusarium wilt for both incidence and severity. The recorded values for disease control using the respective NPs during the protective plan were 82.77, 60.17, 49.67, 38.23, and 70.59%. Meanwhile these values were 92.84, 64.67, 51.33, 45.61, 73.84% during the therapeutic plan. Moreover, CuONPs during the protective plan were the best among the five types of NPs employed in terms of wilt disease management. Regarding the use of these NPs as growth promoters, the obtained results confirmed the effectiveness of the five types of NPs in enhancing vegetative growth of the plant under greenhouse conditions, in comparison with control. Among the five NPs, CuONPs improved the plant vegetative growth and particularly increased the content of the photosynthetic pigments; chlorophyll-a (2.96 mg/g), -b (1.93 mg/g), and total carotenoids (1.16 mg/g). These findings suggest the successful and potential exploitation of nanomaterials in agriculture deployed as nano-based products including nano-fungicides and nano-fertilizers. In terms of sustainability, this promising and exceptional multifunctional role of these nanomaterials will surely exert positive impacts on both the environment and sustainable agriculture.

Biogenic green metal nano systems as efficient anti-cancer agents

Metal/metal oxide nano systems (M-NSs) of tunable and manipulative properties are emerging suitable for cancer management via immunity development, early-stage diagnosis, nanotherapeutics, and targeted drug delivery systems. However, noticeable toxicity, off-targeted actions, lacking biocompatibility, and being expensive limit their acceptability. Moreover, involving high energy (top-down routes) and hazardous chemicals (bottom-up chemical routes) is altering human cycle. To manage such challenges, biomass (plants, microbes, animals) and green chemistry-based M-NSs due to scalability, affordability, are cellular, tissue, and organ acceptability are emerging as desired biogenic M-NSs for cancer management with enhanced features. The state-of-art and perspective of green metal/metal oxide nano systems (GM-NSs) as an efficient anti-cancer agent including, imaging, immunity building elements, site-specific drug delivery, and therapeutics developments are highlighted in this review critically. It is expected that this report will serve as guideline for design and develop high-performance GM-NSs for establishing them as next-generation anti-cancer agent capable to manage cancer in personalized manner.

Mycosynthesis of Zinc Oxide Nanoparticles Exhibits Fungal Species Dependent Morphological Preference

Filamentous fungi can synthesize a variety of nanoparticles (NPs), a process referred to as mycosynthesis that requires little energy input, do not require the use of harsh chemicals, occurs at near neutral pH, and do not produce toxic byproducts. While NP synthesis involves reactions between metal ions and exudates produced by the fungi, the chemical and biochemical parameters underlying this process remain poorly understood. Here, the role of fungal species and precursor salt on the mycosynthesis of zinc oxide (ZnO) NPs is investigated. This data demonstrates that all five fungal species tested are able to produce ZnO structures that can be morphologically classified into i) well-defined NPs, ii) coalesced/dissolving NPs, and iii) micron-sized square plates. Further, species-dependent preferences for these morphologies are observed, suggesting potential differences in the profile or concentration of the biochemical constituents in their individual exudates. This data also demonstrates that mycosynthesis of ZnO NPs is independent of the anion species, with nitrate, sulfate, and chloride showing no effect on NP production. These results enhance the understanding of factors controlling the mycosynthesis of ceramic NPs, supporting future studies that can enable control over the physical and chemical properties of NPs formed through this "green" synthesis method.

An insight into endophytic antimicrobial compounds: an updated analysis

Resistance in micro-organisms against antimicrobial compounds is an emerging phenomenon in the modern era as compared to the traditional world which brings new challenges to discover novel antimicrobial compounds from different available sources, such as, medicinal plants, various micro-organisms, like, bacteria, fungi, algae, actinomycetes, and endophytes. Endophytes reside inside the plants without exerting any harmful impact on the host plant along with providing ample of benefits. In addition, they are capable of producing diverse antimicrobial compounds similar to their host, allowing them to serve as useful micro-organism for a range of therapeutic purposes. In recent years, a large number of studies on the antimicrobial properties of endophytic fungi have been carried out globally. These antimicrobials have been used to treat various bacterial, fungal, and viral infections in humans. In this review, the potential of fungal endophytes to produce diverse antimicrobial compounds along with their various benefits to their host have been focused on. In addition, classification systems of endophytic fungi as well as the need for antimicrobial production with genetic involvement and some of the vital novel antimicrobial compounds of endophytic origin can further be utilized in the pharmaceutical industries for various formulations along with the role of nanoparticles as antimicrobial agents have been highlighted.

Scaling-up strategies for controllable biosynthetic ZnO NPs using cell free-extract of endophytic Streptomyces albus: characterization, statistical optimization, and biomedical activities evaluation

In this study, we identified a suitable precursor and good cellular compartmentalization for enhancing bioactive metabolites to produce biosynthetic zinc oxide nanoparticles (ZnO NPs). An effective medium for cultivating endophytic Streptomyces albus strain E56 was selected using several optimized approaches in order to maximize the yield of biosynthetic ZnO NPs. The highest biosynthetic ZnO NPs yield (4.63 g/L) was obtained when pipetting the mixed cell-free fractions with 100 mM of zinc sulfate as a precursor. The generation of biosynthetic ZnO NPs was quickly verified using a colored solution (white color) and UV-Visible spectroscopy (maximum peak, at 320 nm). On a small scale, the Taguchi method was applied to improve the culture medium for culturing the strain E56. As a result, its cell-dry weight was 3.85 times that of the control condition. And then the biosynthesis of ZnO NPs (7.59 g/L) was increased by 1.6 times. Furthermore, by using the Plackett-Burman design to improve the utilized biogenesis pathway, the biosynthesis of ZnO NPs (18.76 g/L) was increased by 4.3 times. To find the best growth production line, we used batch and fed batch fermentation modes to gradually scale up biomass output. All kinetics of studied cell growth were evaluated during fed-batch fermentation as follows: biomass yield was 271.45 g/L, yield coefficient was 94.25 g/g, and ZnO NPs yield was 345.32 g/L. In vitro, the effects of various dosages of the controllable biosynthetic ZnO NPs as antimicrobial and anticancer agents were also investigated. The treatments with controllable biosynthetic ZnO NPs had a significant impact on all the examined multidrug-resistant human pathogens as well as cancer cells.

Gamma irradiation mediated production improvement of some myco-fabricated nanoparticles and exploring their wound healing, anti-inflammatory and acetylcholinesterase inhibitory potentials

In the current scenario, scaling up the microbial production of nanoparticles with diverse biological applications is an emerging prospect for NPs' sustainable industry. Thus, this paper was conducted to develop a suitable applicative process for the myco-fabrication of cobalt-ferrite (CoFeNPs), selenium (SeNPs), and zinc oxide (ZnONPs) nanoparticles. A strain improvement program using gamma irradiation mutagenesis was applied to improve the NPs-producing ability of the fungal strains. The achieved yields of CoFeNPs, SeNPs, and ZnONPs were intensified by a 14.47, 7.85, and 22.25-fold increase from the initial yield following gamma irradiation and isolation of stable mutant strains. The myco-fabricated CoFeNPs, SeNPs, and ZnONPs were then exploited to study their wound healing, and anti-inflammatory. In addition, the acetylcholinesterase inhibition activities of the myco-fabricated NPs were evaluated and analyzed by molecular docking. The obtained results confirmed the promising wound healing, anti-inflammatory, and acetylcholinesterase inhibition potentials of the three types of NPs. Additionally, data from analyzing the interaction of NPs with acetylcholinesterase enzyme by molecular docking were in conformation with the experimental data.

Metal nanoparticles against multi-drug-resistance bacteria

Antimicrobial-resistant (AMR) bacterial infections remain a significant public health concern. The situation is exacerbated by the rapid development of bacterial resistance to currently available antimicrobials. Metal nanoparticles represent a new perspective in treating AMR due to their unique mechanisms, such as disrupting bacterial cell membrane potential and integrity, biofilm inhibition, reactive oxygen species (ROS) formation, enhancing host immune responses, and inhibiting RNA and protein synthesis by inducing intracellular processes. Metal nanoparticles (MNPs) properties such as size, shape, surface functionalization, surface charges, and co-encapsulated drug delivery capability all play a role in determining their potential against multidrug-resistant bacterial infections. Silver, gold, zinc oxide, selenium, copper, cobalt, and iron oxide nanoparticles have recently been studied extensively against multidrug-resistant bacterial infections. This review aims to provide insight into the size, shape, surface properties, and co-encapsulation of various MNPs in managing multidrug-resistant bacterial infections.

Phytochemical Profile of the Ethanol Extract of Malvaviscus arboreus Red Flower and Investigation of the Antioxidant, Antimicrobial, and Cytotoxic Activities

Flowers are rich sources of bioactive antimicrobial, antioxidant, and anticancer components. This study aimed to determine the constituents of the ethanol extract of Malvaviscus arboreus red flower (ERF) by GC-MS analysis and HPLC identification of phenolic compounds and flavonoids, in addition to the 1HNMR fingerprint. The antimicrobial, antioxidant, and cytotoxic activities of the ERF were investigated. The GC-MS analysis revealed twenty-one components, while HPLC analysis revealed the presence of phenolic and flavonoid compounds. The ERF showed antifungal and antibacterial activity. The highest antibacterial activity was found against Vibrio damsela where a time-kill assay revealed a decline in the amount of viable V. damsela. For fungi, the highest activity was observed against Aspergillus terreus. Using the SRB test on HepG2, the anti-proliferative efficacy of the ERF was evaluated. Cell cycle analysis was utilized to determine autophagic cell death. The ERF prevented the proliferation of the HepG2 cell line with an IC50 of 67.182 µg/µL. The extract primarily promoted apoptosis in HepG2 cells by accumulating hypodiploid cells in the sub-G0/G1 phase, increased caspase 3/7 activity, and caused considerable autophagic cell death in apoptosis-deficient cells. Finally, the observed elevation of cancer cell death indicated that ERF had substantial anticancer potential against HepG2 cells.

An Evaluation of the Biocatalyst for the Synthesis and Application of Zinc Oxide Nanoparticles for Water Remediation—A Review

Global water scarcity is threatening the lives of humans, and it is exacerbated by the contamination of water, which occurs because of increased industrialization and soaring population density. The available conventional physical and chemical water treatment techniques are hazardous to living organisms and are not environmentally friendly, as toxic chemical elements are used during these processes. Nanotechnology has presented a possible way in which to solve these issues by using unique materials with desirable properties. Zinc oxide nanoparticles (ZnO NPs) can be used effectively and efficiently for water treatment, along with other nanotechnologies. Owing to rising concerns regarding the environmental unfriendliness and toxicity of nanomaterials, ZnO NPs have recently been synthesized through biologically available and replenishable sources using a green chemistry or green synthesis protocol. The green-synthesized ZnO NPs are less toxic, more eco-friendly, and more biocompatible than other chemically and physically synthesized materials. In this article, the biogenic synthesis and characterization techniques of ZnO NPs using plants, bacteria, fungi, algae, and biological derivatives are reviewed and discussed. The applications of the biologically prepared ZnO NPs, when used for water treatment, are outlined. Additionally, their mechanisms of action, such as the photocatalytic degradation of dyes, the production of reactive oxygen species (ROS), the generation of compounds such as hydrogen peroxide and superoxide, Zn2+ release to degrade microbes, as well as their adsorbent properties with regard to heavy metals and other contaminants in water bodies, are explained. Furthermore, challenges facing the green synthesis of these nanomaterials are outlined. Future research should focus on how nanomaterials should reach the commercialization stage, and suggestions as to how this ought to be achieved are presented.

Effects of dietary supplementation of myco-fabricated zinc oxide nanoparticles on performance, histological changes, and tissues Zn concentration in broiler chicks

A five weeks biological experiment was planned to investigate the impacts of dietary supplementation with zinc oxide nanoparticles (ZnONPs) synthesized by the endophytic fungus Alternaria tenuissima on productive performance, carcass traits, organ relative weights, serum biochemical parameters, histological alteration in some internal organs and concentration of this element in the serum, liver, thigh and breast muscle in broiler chicks. A total of 108 3-day-old commercial broiler chicks (Cobb 500) were individually weighed and equally distributed in a completely randomized design arrangement according to the dose of ZnONPs supplementation into 3 dietary experimental groups. There were 6 replications having 6 birds per replicate (n = 36/ treatment) for each treatment. The three experiential dietary treatments received corn-soybean meal-based diets enhanced with 0 (control), 40 and 60 mg/kg diet of ZnONPs respectively with feed and water were provided ad libitum consumption through 5 weeks life span. Present results indicated that after 5 weeks of feeding trial and as compared to control, the ZnONPs supplementation groups recorded higher body weight, improved feed consumption, feed conversion ratio and performance index. Serum biochemical analyses revealed that serum cholesterol, triglyceride, low density lipoprotein and uric acid decreased significantly, while high density lipoprotein and liver enzyme concentrations were increased significantly. Meanwhile, zinc accumulation in serum, liver and breast and thigh muscle were linearly increased with increasing zinc supplementation. It could be concluded that supplementation of ZnONPs to broiler diet at 40 or 60 mg/kg improved productive performance, birds' physiological status and the lower levels Zn (40 mg/kg diet) revealed promising results and can be used as an effective feed additive in broilers.

Microbes-mediated synthesis strategies of metal nanoparticles and their potential role in cancer therapeutics

Past few years have seen a paradigm shift towards ecofriendly, green and biological fabrication of metal nanoparticles (MNPs) for diverse nanomedicinal applications especially in cancer nanotheranostics. Besides, the well-known green synthesis methods of plant materials, the potential of the microbial world (bacteria, fungi, alga, etc.) in biofabrication is equally realized. Biomolecules and enzymes in the microbial cells are capable of catalyzing the biosynthesis process. These microbial derived inorganic nanoparticles have been frequently evaluated as potential agents in cancer therapies revealing exciting results. Through, cellular and molecular pathways, these microbial derived nanoparticles are capable of killing the cancer cells. Considering the recent developments in the anticancer applications of microbial derived inorganic MNPs, a dire need was felt to bring the available information to a single document. This manuscript reviews not only the mechanistic aspects of the microbial derived MNPs but also include the diverse mechanisms that governs their anticancer potential. Besides, an updated literature review is presented that includes studies of 2019-onwards.

One-pot green synthesis of ZnO nanoparticles using Scoparia Dulcis plant extract for antimicrobial and antioxidant activities

Nanostructured Zinc oxide (ZnO) materials have attained exciting research interests among various metal oxide nanoparticles due to their unique features. Thus, the scope of applications for ZnO nanoparticles (ZnO NPs) is vast and efficient. The current study demonstrates a simple and environmental-friendly approach for the synthesis of ZnO NPs using the extract of the Scoparia Dulcis. Scoparia Dulcis is a common medicinal plant in Kerala (India) that is traditionally used for its medicinal properties. Morphological characterizations of the as-synthesized ZnO NPs were evaluated using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FESEM). The results revealed that ZnO NPs showed pebble-like morphology and possessed an average particle size of ~ 20 nm. Further, antibacterial and antifungal activities of as-prepared ZnO NPs were investigated against E. coli, Staphylococcus aureus, as well as Candida albicans, and Aspergillus niger, respectively, using the agar-well diffusion method. The results revealed that the prepared ZnO NPs shows excellent antimicrobial activity against the examined microorganisms. Moreover, the antioxidant activity of the as-synthesized ZnO NPs was evaluated using the DPPH assay, which indicated an excellent IC50 value of 1.78 μg/mL that shows high antioxidant activity. All these results proved that the S. dulcis plant extract-mediated synthesis method is a simple, low-cost, eco-friendly procedure for preparing efficient ZnO NPs for biomedical applications.

Biosynthesis of zinc oxide nanoparticles via endophyte Trichoderma viride and evaluation of their antimicrobial and antioxidant properties

The biogenic method for synthesis of nanoparticles is preferred over the traditional strategies, on account of its ease, environmental friendliness, and cost-effectivity, wherein fungi endorse themselves to be the most appropriate precursor for the same. In recent times numerous metal nanoparticles have been reported to exhibit significant therapeutic activities, out of which Zinc Oxide nanoparticles (ZnO NPs) stand apart on account of their multidimensional nature. Thus, this study was carried out with an aim to biosynthesize ZnO NPs utilizing endophyte Trichoderma viride, isolated from the seeds of Momordica charantia. The physicochemical characterization of NPs was done via employing a combination of spectroscopic and microscopic techniques. The NPs were found to have a hexagonal shape and possessed an average particle size of around 63.3 nm. The antimicrobial activity of NPs was evaluated against multi-drug resistant organisms and it was observed to be an appreciable one whereas the antioxidant activity was deduced to be dose-dependent. Thus, these ZnO NPs can be considered as a probable active ingredient of any future therapeutic conceptualization after undertaking a thorough toxicological assessment.

Improving carboxymethyl cellulose edible coating using ZnO nanoparticles from irradiated Alternaria tenuissima

In this paper, gamma-irradiation was successfully used to intensify the yield of Zinc oxide nanoparticles (ZnONPs) produced by the fungus Alternaria tenuissima as a sustainable and green process. The obtained data showed that 500 Gy of gamma-irradiation increased ZnONPs' yield to approximately four-fold. The synthesized ZnONPs were then exploited to develop active Carboxymethyl Cellulose films by casting method at two different concentration of ZnONPs 0.5% and 1.0%. The physicochemical, mechanical, antioxidant, and antimicrobial properties of the prepared films were evaluated. The incorporation of ZnONPs in the Carboxymethyl Cellulose films had significantly decreased solubility (from 78.31% to 66.04% and 59.72%), water vapor permeability (from 0.475 g m-2 to 0.093 g m-2 and 0.026 g m-2), and oxygen transfer rate (from 24.7 × 10-2 to 2.3 × 10-2 and 1.8 × 10-2) of the respective prepared films. Meanwhile, tensile strength (from 183.2 MPa to 203.34 MPa and 235.94 MPa), elongation (from 13.0% to 62.5% and 83.7%), and Yang's modulus (from 325.344 to 1410.0 and 1814.96 MPa) of these films were increased. Moreover, the antioxidant and antimicrobial activities against several human and plant pathogens the prepared of Carboxymethyl Cellulose-ZnONPs films were significantly increased. In conclusion, the prepared Carboxymethyl Cellulose-ZnONPs films showed enhanced activities in comparison with Carboxymethyl Cellulose film without NPs. With these advantages, the fabricated Carboxymethyl Cellulose-ZnONPs films in this study could be effectively utilized as protective edible coating films of food products.

Photocatalytic effect-assisted antimicrobial activities of acrylic resin incorporating zinc oxide nanoflakes

To overcome the deficiency of the antimicrobial effect of polymer, zinc oxide nanoparticles have been widely utilized as advanced nanofillers due to their antimicrobial and photocatalytic activity. However, the underlying antimicrobial mechanism has not been fully understood apart from topological and physical characteristics. In this study, we prepared zinc oxide nanoparticles-based acrylic resin to explore its antimicrobial mechanism under controlled mechanophysical conditions by using silane-treated zinc oxide nanoflakes (S-ZnNFs). S-ZnNFs incorporated acrylic resin (poly(methyl methacrylate), PMMA) composites up to 2 wt% were selected based on comparable mechanophysical properties (e.g., roughness, wettability, strength and hardness), possibly affecting antimicrobial properties beyond the zinc oxide nanoparticle effect, to bare PMMA. Antimicrobial adhesion results were still observed in 2 wt% S-ZnNFs incorporated PMMA using Candida albicans (C. albicans), one of the fungal infection species. In order to confirm the antimicrobial effects by photocatalysis, we pre-exposed the UV light on 2 wt% S-ZnNF composites before cell seeding, revealing synergetic antimicrobial effect via additional reactive oxygen species (ROS) generation to C. albicans over zinc oxide nanoparticle-induced one. RNA-seq analysis revealed distinguished cellular responses between zinc oxide nanoparticles and UV-mediated photocatalytic effect, but both linked to generation of intracellular ROS. Thus, the above data suggest that induction of high intracellular ROS of C. albicans was the main antimicrobial mechanism under controlled mechanophysical parameters and synergetic ROS accumulation can be induced by photocatalysis, recapitulating a promising use of a S-ZnNFs or possibly zinc oxide nanoparticles as intracellular-ROS-generating antimicrobial nanofillers in acrylic composite for biomedical applications.

Catalytic potential of endophytes facilitates synthesis of biometallic zinc oxide nanoparticles for agricultural application

Recent advances fascinated the use of biological resources in combination with metals to obtain high quality biometals and apply its advantages in different fields. Endophytic mediated Zinc oxide nanoparticles (ZnO-NPs) is an economical and ecofriendly way for farmers to avoid Zn deficiency in rice crop and obtain high yield. Here we synthesized ZnO-NPs utilizing endophytic bacterial strain of Enterobacter hormaechei (E. hormaechei). The physiochemical properties of the prepared NPs were determined through UV-Vis spectroscopy, XRD, FT-IR, SEM and TEM. The prepared NPs revealed surface plasmon resonance (SPR) at 320 nm (nm) and crystalline structure with 21 nm average crystalline size. FT-IR spectra showed the presence of carboxylic, alcohol and amine functional groups, which confirm the biometallic assembling of the ZnO and endophytic bacterial functional groups. SEM showed pyramidal symmetry whereas TEM revealed poly dispersed spherical shape with particle size distribution 18-48 nm. Our results showed that prepared NPs possess significant antifungal, antibacterial and antioxidant potential at 25, 50 and 100 µg/mL concentrations. Moreover, Cytotoxic and hemolytic assay showed significant results (less % viability and hemolysis activity) at 50 and 100 µg/mL (ZnO-NP's) concentrations as compared to control. The prepared ZnO-NPs were used as bio fertilizer in various concentrations as a foliar spray, which showed significant enhancement of the rice plant growth, along with chlorophyll, proteins and carotenoid contents. These results recommend that endophytic mediated ZnO-NPs are biocompatible and possess significant potential for agricultural applications.

Microbial Mediated Synthesis of Zinc Oxide Nanoparticles, Characterization and Multifaceted Applications

Nanoparticles have gained considerable importance compared to bulk counterparts due to their unique properties. Due to their high surface to volume ratio and high reactivity, metallic and metal-oxide nanostructures have shown great potential applications. Among them, zinc oxide nanoparticles (ZnONPs) have gained tremendous attention attributed to their unique properties such as low toxicity, biocompatibility, simplicity, easy fabrication, and environmental friendly. Remarkably, ZnONPs exhibit optical, physical, antimicrobial, anticancer, anti-inflammatory and wound healing properties. These nanoparticles have been applied in various fields such as in biomedicine, biosensors, electronics, food, cosmetic industries, textile, agriculture and environment. The synthesis of ZnONPs can be performed by chemical, physical and biological methods. Although the chemical and physical methods suffer from some disadvantages such as the involvement of high temperature and pressure conditions, high cost and not environmentally friendly, the green synthesis of ZnONPs offers a promising substitute to these conventional methods. On that account, the microbial mediated synthesis of ZnONPs is clean, eco-friendly, nontoxic and biocompatible method. This paper reviews the microbial synthesis of ZnONPs, parameters used for the optimization process and their physicochemical properties. The potential applications of ZnONPs in biomedical, agricultural and environmental fields as well as their toxic aspects on human beings and animals have been reviewed.

Harnessing endophytic fungi for biosynthesis of selenium nanoparticles and exploring their bioactivities

In the light of the fast growing several applications of selenium nanoparticles (SeNPs) in different industrial and agricultural sectors, this paper was conducted to explore the suitability of endophytic fungi as nano-factories for SeNPs. Thus, 75 fungal isolates were recovered from plant tissues and tested for their efficacy to biosynthesize SeNPs. Four promising strains were found able to synthesis SeNPs with different characteristics and identified. These strains were Aspergillus quadrilineatus isolated from the twigs of Ricinus communis, Aspergillus ochraceus isolated from the leaves of Ricinus communis, Aspergillus terreus isolated from the twigs of Azadirachta indica, and Fusarium equiseti isolated from the twigs of Hibiscus rose-sinensis. The synthesized SeNPs were characterized by several techniques viz., UV–Vis, X-ray diffraction, Dynamic light scattering analyses, High resolution transmission electron microscopy, and Fourier transform infrared spectroscopy, to study their crystalline structure, particle sized distribution, and morphology. Furthermore, the in vitro antimicrobial and antioxidant activities were evaluated. SeNPs synthesized by the four strains showed potent antifungal and antibacterial potentials against different human and phyto- pathogens. Moreover, SeNPs synthesized by the respective strains showed promising antioxidant power with IC₅₀ values of 198.32, 151.23, 100.31, and 91.52 µg mL^− 1. To the best of our knowledge, this is the first study on the use of endophytic fungi for SeNPs’ biosynthesis. The presented research recommends the use of endophytic fungi as facile one-pot production bio-factories of SeNPs with promising characteristics.

Discovery of four different promising endophytic fungi for a facile-synthesis of SeNPs.

SeNPs were successfully mycosynthesized and characterized.

SeNPs exhibited promising antifungal, antibacterial, and antioxidant activities.

Applicability of bio-synthesized nanoparticles in fungal secondary metabolites products and plant extracts for eliminating antibiotic-resistant bacteria risks in non-clinical environments

The abundance of antibiotic-resistant bacteria in the prawn pond effluents can substantially impact the natural environment. The settlement ponds, which are the most common treatment method for farms wastewater, might effectively reduce the suspended solids and organic matter. However, the method is insufficient for bacterial inactivation. The current paper seeks to highlight the environmental issue associated with the distribution of antibiotic resistant bacteria (ARB) from prawn farm wastewater and their impact on the microbial complex community in the surface water which receiving these wastes. The inactivation of antibiotic-resistant bacteria in prawn wastewater is strongly recommended because the presence of antibiotic-resistant bacteria in the environment causes water pollution and public health issues. The nanoparticles are more efficient for bacterial inactivation. They are widely accepted due to their high chemical and mechanical stability, broad spectrum of radiation absorption, high catalytic activity, and high antimicrobial activity. Many studies have examined the use of fungi or plants extract to synthesis zinc oxide nanoparticles (ZnO NPs). It is evident from recent papers in the literature that green synthesized ZnO NPs from microbes and plant extracts are non-toxic and effective. ZnO NPs inactivate the bacterial cells as a function for releasing reactive oxygen species (ROS) and zinc ions. The inactivation of antibiotic-resistant bacteria tends to be more than 90% which exhibit strong antimicrobial behavior against bacterial species.

Application of Metal Nanoparticles for Production of Self-Sterilizing Coatings

Metal nanoparticles (NPs) are increasingly being used in many areas, e.g., industry, pharmacy, and biomedical engineering. NPs can be obtained through chemical and biological synthesis or using physical methods. AgNPs, AuNPs, CuNPs, FeNPs, MgNPs, SnO2NPs, TiO2NPs, and ZnONPs are the most commonly synthesized metal nanoparticles. Many of them have anti-microbial properties and documented activity supported by many tests against some species of pathogenic bacteria, viruses, and fungi. AgNPs, which are used for the production of commercial self-sterilizing packages, are one of the best-explored nanoparticles. Moreover, the EFSA has approved the use of small doses of silver nanoparticles (0.05 mg Ag·kg−1) to food products. Recent studies have shown that metal NPs can be used for the production of coatings to prevent the spread of the SARS-CoV-2 virus, which has caused the global pandemic. Some nanoparticles (e.g., ZnONPs and MgONPs) have the Generally Recognized As Safe (GRAS) status, i.e., they are considered safe for consumption and can be used for the production of edible coatings, protecting food against spoilage. Promising results have been obtained in research on the use of more than one type of nanometals, which prevents the development of pathogen resistance through various mechanisms of inactivation thereof.

Exploiting the exceptional biosynthetic potency of the endophytic Aspergillus terreus in enhancing production of Co3O4, CuO, Fe3O4, NiO, and ZnO nanoparticles using bioprocess optimization and gamma irradiation

Developing a suitable applicative process and scaling up the microbial synthesis of nanomaterials is an attractive and emerging prospect for a future sustainable industrial production. In this paper, optimization of fermentation conditions for enhanced production of Co₃O₄, CuO, Fe₃O₄, NiO, and ZnO nanoparticles by the endophytic A. terreus ORG-1 was studied. Different cultivation conditions were evaluated. Then, a response surface methodology program was used to optimize physical conditions controlling the biosynthesis of these NPs. Finally, the use of gamma irradiation for improvement of NPs’ production was adopted. Under the optimum conditions and after gamma irradiation, the final yields of the respective NPs reached 545.71, 651.67, 463.19, 954.88, 1356.42 mg L⁻¹. To the best of our knowledge, this is the first report on the production and enhancement of different types of nanomaterials from one microbial culture that can open up the way towards the industrialization of the microbial production of nanomaterials.

Current advancements on the fabrication, modification, and industrial application of zinc oxide as photocatalyst in the removal of organic and inorganic contaminants in aquatic systems

Industrial wastewaters contain hazardous contaminants that pollute the environment and cause socioeconomic problems, thus demanding the employment of effective remediation procedures such as photocatalysis. Zinc oxide (ZnO) nanomaterials have emerged to be a promising photocatalyst for the removal of pollutants in wastewater owing to their excellent and attractive characteristics. The dynamic tunable features of ZnO allow a wide range of functionalization for enhanced photocatalytic efficiency. The current review summarizes the recent advances in the fabrication, modification, and industrial application of ZnO photocatalyst based on the analysis of the latest studies, including the following aspects: (1) overview on the properties, structures, and features of ZnO, (2) employment of dopants, heterojunction, and immobilization techniques for improved photodegradation performance, (3) applicability of suspended and immobilized photocatalytic systems, (4) application of ZnO hybrids for the removal of various types of hazardous pollutants from different wastewater sources in industries, and (5) potential of bio-inspired ZnO hybrid nanomaterials for photocatalytic applications using renewable and biodegradable resources for greener photocatalytic technologies. In addition, the knowledge gap in this field of work is also highlighted.

Multifunctional Eco-Friendly Synthesis of ZnO Nanoparticles in Biomedical Applications

This work describes an environmental-friendly preparation of ZnO nanoparticles using aqueous oat extract. The advanced electrochemical and optical features of green synthesized ZnONPs displayed excellent antibacterial activity and exhibited an important role in pharmaceutical determinations. The formation of nanoscale ZnO was confirmed using various spectroscopic and microscopic investigations. The formed nanoparticles were found to be around 100 nm. The as-prepared ZnONPs were monitored for their antibacterial potential against different bacterial strains. The inhibition zones for ZnONPs were found as Escherichia coli (16 mm), Pseudomonas aeruginosa (17 mm), Staphylococcus aureus (12 mm) and Bacillus subtilis (11 mm) using a 30-µg mL-1 sample concentration. In addition, ZnONPs exhibited significant antioxidant effects, from 58 to 67%, with an average IC50 value of 0.88 ± 0.03 scavenging activity and from 53 to 71% (IC50 value of 0.73 ± 0.05) versus the scavenging free radicals DPPH and ABTS, respectively. The photocatalytic potential of ZnONPs for Rhodamine B dye degradation under UV irradiation was calculated. The photodegradation process was carried out as a function of time-dependent and complete degradation (nearly 98%), with color removal after 120 min. Conclusively, the synthesized ZnONPs using oat biomass might provide a great promise in the future for biomedical applications.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Whey Proteins-Zinc Oxide Bionanocomposite as Antibacterial Films

The use of toxic crosslinking agents and reagents in the fabrication of hydrogels is a frequent issue which is particularly concerning for biomedical or food packaging applications. In this study, novel antibacterial bionanocomposite films were obtained through a simple solvent casting technique without using any crosslinking substance. Films were made from a flexible and transparent whey protein matrix containing zinc oxide nanoparticles synthesised via a wet chemical precipitation route. The physicochemical and functional properties of the ZnO nanoparticles and of the composite films were characterised, and their antibacterial activity was tested against S. epidermidis and E. coli. The synthesised ZnO nanoparticles had an average size of about 30 nm and a specific surface area of 49.5 m2/g. The swelling ratio of the bionanocomposite films increased at basic pH, which is an appealing feature in relation to the absorption of chronic wound exudate. A n-ZnO concentration-dependent antibacterial effect was observed for composite films. In particular, marked antibacterial activity was observed against S. epidermidis. Overall, these findings suggest that this novel material can be a promising and sustainable alternative in the design of advanced solutions for wound dressing or food packaging.

A state of the art review on the synthesis, antibacterial, antioxidant, antidiabetic and tissue regeneration activities of zinc oxide nanoparticles

Recently, zinc oxide nanoparticles (ZnONPs) are gaining much interest of nanobiotechnologists due to their profound biomedical applications. ZnONPs are used as antibacterial agents, which cause both gram-positive and negative bacterial cell death through the generation of reactive free radicals as well as membrane rupture. ZnONPs show excellent antioxidant properties in normal mammalian cells via the scavenging of reactive free radicals and up-regulation of antioxidant enzyme activities. Besides, it also shows hypoglycaemic effect in diabetic animals via pancreatic β-cells mediated increased insulin secretion and glucose uptake by liver, skeletal muscles and adipose tissues. Among the other potential applications, ZnONPs-induced bone and soft-tissue regeneration open a new horizon in the field of tissue engineering. Here, first we reviewed the complete synthesis routes of ZnONPs by physical, chemical, and biological pathways as well as outlined the advantages and disadvantages of the techniques. Further, we discussed the several important aspects of physicochemical analysis of ZnONPs. Additionally, we extensively reviewed the important biomedical applications of ZnONPs as antibacterial, antioxidant, and antidiabetic agents, and in the field of tissue engineering with special emphasis on their mechanisms of actions. Furthermore, the future perspectives of the ZnONPs are also discussed.

Cell-free extract assisted synthesis of ZnO nanoparticles using aquatic bacterial strains: Biological activities and toxicological evaluation

The introduction of novel bacterial strains and the development of microbial approaches for nanoparticles biosynthesis could minimize the negative environmental impact and eliminate the concern and challenges of the available approaches. In this study, a biological method based on microbial cell-free extract was used for biosynthesis of ZnO NPs using two new aquatic bacteria, Marinobacter sp. 2C8 and Vibrio sp. VLA. The synthesized ZnO NPs were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscope (AFM), dynamic light scattering (DLS) and zeta potential. The UV-Visible absorption peak was found to be at 266 and 250 nm for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. FTIR study suggested that the hydroxyl, amine, and carboxyl groups of bacterial proteins are mainly responsible for stabilizing the biosynthesized ZnO NPs. The formation of hexagonal wurtzite structure of ZnO NPs was confirmed by the XRD pattern. The morphology of the nanoparticles was found to be spherical with the average particle size of about 10.23 ± 2.48 nm and 20.26 ± 4.44 nm for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. The values of zeta potential indicate the high stability of the biosynthesized ZnO NP. Zeta potential values indicated the high stability of the biosynthesized ZnO NP and were obtained -20.54 ± 7.15 and -23.87 ± 2.29 mV for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. The biosynthesized ZnO NPs had antibacterial activity against Gram-negative and Gram-positive strains and possessed excellent antibiofilm activity with the maximum inhibition of about 96.55% at 250 µg/mL. The DPPH activity of ZnO-2C8 NPs and ZnO-VLA NPs were found 88.9% and 85.7% for 2500 μg/mL concentration, respectively. The toxicity test revealed the biocompatibility of the biosynthesized ZnO NPs. The results suggested that this approach is a very good route for synthesizing ZnO NPs with potential applications in biotechnology.

Eco-friendly Mycogenic Synthesis of ZnO and CuO Nanoparticles for In Vitro Antibacterial, Antibiofilm, and Antifungal Applications

Mycogenic synthesis of medically applied zinc oxide (ZnO) and copper oxide (CuO) nanoparticles (NPs) were exploited using Penicillium chrysogenum. The biogenesis and capping processes of the produced nano-metals were conducted by functional fungal extracellular enzymes and proteins. The obtained ZnO-NPs and CuO-NPs were characterized. Also, the antibacterial activity and minimum inhibitory concentration (MIC) values of ZnO-NPs and CuO-NPs were determined. Also, antibiofilm and antifungal activities were investigated. Results have demonstrated the ability of the bio-secreted proteins to cape and reduce ZnO and CuO to hexagonal and spherical ZnO-NPs and CuO-NPs with particle size at 9.0-35.0 nm and 10.5-59.7 nm, respectively. Both ZnO-NPs and CuO-NPs showed high antimicrobial activities not only against Gram-positive and Gram-negative bacteria but also against some phytopathogenic fungal strains. Besides this, those NPs showed varied antibiofilm effects against different microorganisms. Quantitative and qualitative analyses indicated that CuO-NPs had an effective antibiofilm activity against Staphylococcus aureus and therefore can be applied in diverse medical devices. Thus, the mycogenic green synthesized ZnO-NPs and CuO-NPs have the potential as smart nano-materials to be used in the medical field to limit the spread of some pathogenic microbes.

Metal-Fungus interaction: Review on cellular processes underlying heavy metal detoxification and synthesis of metal nanoparticles

The most adverse outcome of increasing industrialization is contamination of the ecosystem with heavy metals. Toxic heavy metals possess a deleterious effect on all forms of biota; however, they affect the microbial system directly. These heavy metals form complexes with the microbial system by forming covalent and ionic bonds and affecting them at the cellular level and biochemical and molecular levels, ultimately leading to mutation affecting the microbial population. Microbes, in turn, have developed efficient resistance mechanisms to cope with metal toxicity. This review focuses on the vital tolerance mechanisms employed by the fungus to resist the toxicity caused by heavy metals. The tolerance mechanisms have been basically categorized into biosorption, bioaccumulation, biotransformation, and efflux of metal ions. The mechanisms of tolerance to some toxic metals as copper, arsenic, zinc, cadmium, and nickel have been discussed. The article summarizes and provides a detailed illustration of the tolerance means with specific examples in each case. Exposure of metals to fungal cells leads to a response that may lead to the formation of metal nanoparticles to overcome the toxicity by immobilization in less toxic forms. Therefore, fungal-mediated green synthesis of metal nanoparticles, their mechanism of synthesis, and applications have also been discussed. An understanding of how fungus resists metal toxicity can provide insights into the development of adaption techniques and methodologies for detoxification and removal of metals from the environment.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Synthesis and Biological Evaluation of Amoxicillin Loaded Hybrid Material Composite Spheres Against Methicillin-Resistant Staphylococcus aureus

BACKGROUND

Incoherent use of antibiotics has led toward resistance in MRSA, becoming multidrug-resistant with a high rate of virulence in the community and hospital settings.

OBJECTIVE

Synergistic anti-MRSA activity was investigated in this study for hybrid material composite spheres of amoxicillin, Ag nanoparticles, and chitosan, which were prepared by one-step synthesis method, and various characterizations were performed.

METHODS

Antimicrobial-susceptibility assay on MRSA was achieved by disc diffusion and agar dilution techniques, while agar well diffusion was used for hybrid composite spheres. The in vitro and cytotoxicity studies were conducted on the skin abrasion mouse model and MTT assay on RD cell, respectively.

RESULTS

All isolates showed resistance to the tested antibiotics except vancomycin. MIC against MRSA showed high resistance with amoxicillin from 4 to 128 mg L^-1. The mean diameter of chitosan spheres and Ag nanoparticles was 02 mm and 277 nm, respectively. Morphology of spheres was uneven, varied, porous, and irregular in SEM, and Ag nanoparticles presence and formation was also seen in the micrograph. No substantial interface among drug, nanoparticles, and polymer was found in XRD, and IR showed characteristic peaks of all compounds in the formulation. The in vitro assay showed augmented anti-MRSA activity with amoxicillin loaded hybrid composite spheres (22-29 mm). A significant reduction in microbial burden (~6.5 log₁₀ CFU mL^-1) was seen in vivo with loaded hybrid composite spheres formulation. The MTT assay indicated no potential cytotoxicity with hybrid composite spheres.

CONCLUSION

The synergistic effect of Amoxycillin in the current study predicts a promising hybrid formulation with enhanced anti-MRSA activity.

Discovery of the anticancer drug vinblastine from the endophytic Alternaria alternata and yield improvement by gamma irradiation mutagenesis

AIMS

Several fungal endophytes were isolated from some medicinal plants and screened for their ability to produce the anticancer drug vinblastine.

METHODS AND RESULTS

An isolate was found to produce vinblastine (205·38 μg l^-1 ), and the identity of the fungal vinblastine was confirmed by UV spectroscopic, high-performance liquid chromatography and electrospray ionization mass spectrometry analyses. Based on both morphological and molecular studies, the vinblastine-producing strain was identified as Alternaria alternata. Cytotoxic activities of the fungal vinblastine were evaluated against CHO-K1, MCF-7 and HepG-2 cell lines by the MTT assay. The proliferation of these cell lines was inhibited after treatment with fungal vinblastine and the recorded IC₅₀ values of the respective cell lines were 12·15, 8·55 and 7·48 μg ml^-1 . A strain improvement programme for improving vinblastine productivity by the fungal strain was also used. In addition, 10 broth media were evaluated for further increasing the production of vinblastine. The yield of vinblastine was intensified by 3·98-fold following gamma irradiation at 1000 Gy, and a stable mutant strain was isolated. Among the screened media, M1D broth (pH 6·0) stimulated the highest vinblastine production of 1553·62 μg l^-1 by the isolated mutant strain.

CONCLUSIONS

The present study is the first report on the production and yield improvement of the anticancer drug vinblastine by A. alternata.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings suggest A. alternata as a viable and potent source with excellent biotechnological potential for the production of vinblastine.

Endophytic Nanotechnology: An Approach to Study Scope and Potential Applications

Nanotechnology has become a very advanced and popular form of technology with huge potentials. Nanotechnology has been very well explored in the fields of electronics, automobiles, construction, medicine, and cosmetics, but the exploration of nanotecnology's use in agriculture is still limited. Due to climate change, each year around 40% of crops face abiotic and biotic stress; with the global demand for food increasing, nanotechnology is seen as the best method to mitigate challenges in disease management in crops by reducing the use of chemical inputs such as herbicides, pesticides, and fungicides. The use of these toxic chemicals is potentially harmful to humans and the environment. Therefore, using NPs as fungicides/ bactericides or as nanofertilizers, due to their small size and high surface area with high reactivity, reduces the problems in plant disease management. There are several methods that have been used to synthesize NPs, such as physical and chemical methods. Specially, we need ecofriendly and nontoxic methods for the synthesis of NPs. Some biological organisms like plants, algae, yeast, bacteria, actinomycetes, and fungi have emerged as superlative candidates for the biological synthesis of NPs (also considered as green synthesis). Among these biological methods, endophytic microorganisms have been widely used to synthesize NPs with low metallic ions, which opens a new possibility on the edge of biological nanotechnology. In this review, we will have discussed the different methods of synthesis of NPs, such as top-down, bottom-up, and green synthesis (specially including endophytic microorganisms) methods, their mechanisms, different forms of NPs, such as magnesium oxide nanoparticles (MgO-NPs), copper nanoparticles (Cu-NPs), chitosan nanoparticles (CS-NPs), β-d-glucan nanoparticles (GNPs), and engineered nanoparticles (quantum dots, metalloids, nonmetals, carbon nanomaterials, dendrimers, and liposomes), and their molecular approaches in various aspects. At the molecular level, nanoparticles, such as mesoporous silica nanoparticles (MSN) and RNA-interference molecules, can also be used as molecular tools to carry genetic material during genetic engineering of plants. In plant disease management, NPs can be used as biosensors to diagnose the disease.