Sustainable lipid production from oleaginous fungus Syncephalastrum racemosum using synthetic and watermelon peel waste media

Antimicrobial, anticancer activities, molecular docking, and DFT/B3LYP/LANL2DZ analysis of heterocyclic cellulose derivative and their Cu-complexes

In this study, novel Cu-complexes of heterocyclic cellulose which were synthesized via the reaction of carboxymethyl cellulose (CMC) from bagasse pulp with NH2NH2 to give hydrazide cellulose which easily reacted with CS2 to form salt and then cyclized in the presence of HCl to afford cellulose oxadiazole, or with hydrazine hydrate to give cellulose triazole. Furthermore, the cellulose oxadiazole and triazole moieties acting as chelating agents with metal ion Cu (II), and all synthesized compounds were examined for their spectral analysis to show the adsorption of Cu (II) on the surface of cellulose through intramolecular hydrogen bonding. Results illustrated that cellulose oxadiazole and Cu- cellulose oxadiazole exhibited antimicrobial activities more than triazole and Cu- cellulose triazole. Furthermore, anticancer results showed that both cellulose oxadiazole and triazole exhibited activity higher than Cu-cellulose oxadiazole and Cu-cellulose triazole, where the cellulose triazole showed the highest activity (IC50 = 58.7 μg/μL). Additionally, the docking simulation of the synthesized cellulose complexes with different proteins such as PDBID:3t88, PDBID:4ynt, PDBID:1tgh, PDBID:2wje, and PDBID:4hdq and shortage bond length to confirm the experimental results. Optimization of metal complexes utilized the DFT/B3LYP/LANL2DZ basis set to confirm the stability of these metals theoretically and their physical descriptors and FMO analysis.

Synthetic strategy towards novel composite based on substituted pyrido[2,1-b][1,3,4]oxadiazine-dialdehyde chitosan conjugate with antimicrobial and anticancer activities

Synthesis of new compounds that have biological activity is an indispensible issue in order to deal with the drug resistant bacteria. This wok reports preparation of a novel composite based on substituted pyrido[2,1-b][1,3,4] oxadiazine-dialdehyde chitosan (PODACs) conjugate. Firstly, a novel approach of synthesizing of a new substituted pyrido[2,1-b][1,3,4]oxadiazine-7-carboxylic acid (PO) is reported through reacting(Z)-N'-(1-(3-aminophenyl)ethylidene)-2-cyanoacetohydrazide with (Z)-ethyl 2-cyano-3-(pyridin-3-yl)acrylate. Then Dialdehyde chitosan (DACs) has prepared via periodat oxidation of chitosan (Cs). The synthesized compounds have studied via various spectroscopic instruments to validate their chemical structure such as nuclear magnetic resonance 1 H NMR, ¹³ C NMR, fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). The substituted pyrido [2,1-b][1,3,4]oxadiazine and the composite were evaluated for antimicrobial activity against pathogenic bacteria and unicellular fungi. The results revealed that, the composite exhibited promising antimicrobial activity against E. coli, S. aureus, B. subtilis and C. albicans where inhibition zones were 19, 18, 36 and 20 mm respectively. Furthermore, the substituted pyrido [2,1-b][1,3,4]oxadiazine and the composite were evaluated for cytotoxic activity against MCF-7 human breast cancer cell line as well as vero normal cell line. Results illustrated the prepared composite has anticancer activity against MCF7 where IC₅₀ was 238 µg/ml.

Green nanocoating-based polysaccharides decorated with ZnONPs doped Egyptian kaolinite for antimicrobial coating paper

Paper coating plays an important role in the paper properties, printability and application. The nanocoating is a multifunction layer that provides the paper with unique features. In this work, nanocoating formulas were prepared using a green method and component. The nanocoating formulas were based on biopolymers nanostarch NSt and nanochitosan NCh (NCS) decorated with Egyptian kaolinite Ka doped with zinc nanoparticles NCS@xka/ZnONPs (x represents different ratios) support for multifunctional uses. The nanocoating formulas were characterized using a physiochemical analysis as well as a topographical study. FTIR, XRD, SEM and TEM techniques were used. Additionally, the antimicrobial activity of the tested samples was assessed against six microorganisms including Gram-negative and Gram-positive bacteria. The prepared nanocoating formulas affirmed excellent antimicrobial activity as a broad-spectrum antimicrobial active agent with excellent activity against all representative microbial communities. The nanocoating with the highest ratio of Ka/ZnONPs (NCS@40 ka/ZnONPs) showed excellent antimicrobial activity with an inhibition percentage of more than 70% versus all microorganisms presented. The paper was coated with the prepared suspensions and characterized concerning optical, mechanical and physical properties. When Ka/ZnONPs were loaded into NCS in a variety of ratios, the characteristics of coated paper were enhanced compared to blank paper. The sample NCS@40 ka/ZnONPs increased tensile strength by 11%, reduced light scattering by 12%, and improved brightness and whiteness by 1%. Paper coated with NCh suspension had 35.32% less roughness and 188.6% less porosity. When coated with the sample NCS@10 ka/ZnONPs, the coated paper's porosity was reduced by 94% and its roughness was reduced by 10.85%. The greatest reduction in water absorptivity was attained by coating with the same sample, with a reduction percentage of 132%.

Development of a chitosan derivative bearing the thiadiazole moiety and evaluation of its antifungal and larvicidal efficacy

A new chitosan derivative bearing a new thiadiazole compound was developed, and its antifungal and larvicidal activities were investigated. The chitosan derivative (coded here as PTDz-Cs) was synthesized by the reaction between the carboxylic derivative of the thiadiazole moiety and chitosan. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H/13C-NMR), gas chromatography–mass spectrometry (GC–MS), elemental analysis, X-Ray diffraction (XRD), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) were used to characterize the developed derivatives. Compared to chitosan, the PTDz-Cs derivative has a less crystalline structure and less thermal stability. The antifungal results revealed that PTDz-Cs exhibited potential activity against Rhizopus microspores, Mucor racemosus, Lichtheimia corymbifera, and Syncephalastrum racemosum where inhibition zones were 17.76, 20.1, 38.2, and 18.3 mm, respectively. The larvicidal efficacy of the PTDz-Cs derivative against A. stephensi larvae was tested, and the results exposed that the LC50 and LC90 values (first instar) were 5.432 and 10.398 ppm, respectively, indicating the high susceptibility of early instar mosquito larvae to PTDz-Cs. These results emphasize that this study provided a new chitosan derivative that could be potentially used in the biomedical fields.

A multi-aspect analysis of two analogous aspergillus spp. belonging to section Flavi: aspergillus flavus and aspergillus oryzae

Microfungal isolates were routinely identified depending on both macro and micro morphological characteristics, sometimes, some fungal isolates appeared to be similar and such cases caused severe confusion for mycologists during the preliminary identification. During our previous studies dealing with isolation of fungi for some biotechnological applications; two mystifying species Aspergillus flavus and Aspergillus oryzae showed similar cultural and macroscopic features. Therefore, the current study aimed to easily distinguish between these two species depending on simple approaches which are routinely followed by a large segment of researchers. Investigation of the macroscopic features was performed to check the fungal growth on four different media (PDA, MEA, YES, and CYA) followed by microscopic examination using an ordinary light microscope, and scanning electron microscope SEM. Also, screening of secondary metabolites for both strains was preliminarily identified to find out the difference between their metabolic profiles. Finally, ITS rDNA was involved to clarify the molecular differences along their partial sequence. Conclusively, the BLAST strategy confirmed the similarity of ITS rDNA segments of both fungal strains that supported our hypothesis. The color of the fungal growth is a very critical factor whereas it is extensively influenced by the type of cultivation media. Accordingly, the YES medium was an inspiring tool assisting in prompt differentiation during the culture investigation step whereas A. oryzae and A. flavus appeared significant mustard yellow and olive green respectively. During the microscopic examination, the CYA medium also had a robust effect on the formation of the conidial chain whereas the knit long chain was observed in A. oryzae while the conidia appeared scattered and not in a chain in the case of A. flavus. Likewise, both two strains possessed different metabolic profiles where A. oryzae is not an Afla toxin producer, unlike A. flavus.

Efficient use of discarded vegetal residues as cost-effective feedstocks for microbial oil production

BACKGROUND

Horticultural intensive type systems dedicated in producing greenhouse vegetables are one of the primary industries generating organic waste. Towards the implementation of a zero-waste strategy, this work aims to use discarded vegetables (tomato, pepper and watermelon) as feedstock for producing microbial oil using the oleaginous yeast Cryptococcus curvatus.

RESULTS

The soluble fraction, resulting after crushing and centrifuging these residues, showed C/N ratios of about 15, with a total carbohydrate content (mainly glucose, fructose and sucrose) ranging from 30 g/L to 65 g/L. Using these liquid fractions as substrate under a pulse-feeding strategy with a concentrated glucose solution resulted in an intracellular total lipid accumulation of about 30% (w/w) of the total dry cell weight (DCW). To increase this intracellular lipid content, the initial C/N content was increased from 15 to 30 and 50. Under these conditions, the process performance of the pulse-feeding strategy increased by 20-36%, resulting in a total intracellular lipid concentration of 35-40% DCW (w/w).

CONCLUSION

These results demonstrate the potential of discarded vegetables as a substrate for producing bio-based products such as microbial oil when proper cultivation strategies are available.

Comparative Genomics of Mortierellaceae Provides Insights into Lipid Metabolism: Two Novel Types of Fatty Acid Synthase

Fungal species in the family Mortierellaceae are important for their remarkable capability to synthesize large amounts of polyunsaturated fatty acids, especially arachidonic acid (ARA). Although many genomes have been published, the quality of these data is not satisfactory, resulting in an incomplete understanding of the lipid pathway in Mortierellaceae. We provide herein two novel and high-quality genomes with 55.32% of syntenic gene pairs for Mortierella alpina CGMCC 20262 and M. schmuckeri CGMCC 20261, spanning 28 scaffolds of 40.22 Mb and 25 scaffolds of 49.24 Mb, respectively. The relative smaller genome for the former is due to fewer protein-coding gene models (11,761 vs. 13,051). The former yields 45.57% of ARA in total fatty acids, while the latter 6.95%. The accumulation of ARA is speculated to be associated with delta-5 desaturase (Delta5) and elongation of very long chain fatty acids protein 3 (ELOVL3). A further genomic comparison of 19 strains in 10 species in three genera in the Mortierellaceae reveals three types of fatty acid synthase (FAS), two of which are new to science. The most common type I exists in 16 strains of eight species of three genera, and was discovered previously and consists of a single unit with eight active sites. The newly revealed type II exists only in M. antarctica KOD 1030 where the unit is separated into two subunits α and β comprised of three and five active sites, respectively. Another newly revealed type III exists in M. alpina AD071 and Dissophora globulifera REB-010B, similar to type II but different in having one more acyl carrier protein domain in the α subunit. This study provides novel insights into the enzymes related to the lipid metabolism, especially the ARA-related Delta5, ELOVL3, and FAS, laying a foundation for genetic engineering of Mortierellaceae to modulate yield in polyunsaturated fatty acids.

Antagonistic Effect of Plant Growth-Promoting Fungi Against Fusarium Wilt Disease in Tomato: In vitro and In vivo Study

Fusarium wilt is considered one of the most destructive diseases for tomato plants. The novelty of this work was to investigate the antifungal and plant growth-promoting capabilities of some plant growth-promoting fungi (PGPF). Plant growth-promoting fungi (PGPF) improved the plant health and control plant infections. In this study, two fungal strains as PGPF were isolated and identified as Aspergillus fumigatus and Rhizopus oryzae using molecular method. The extracts of A. fumigatus and R. oryzae exhibited promising antifungal activity against F. oxysporum in vitro. Moreover, antagonistic effect of A. fumigatus and R. oryzae against F. oxysporum causing tomato wilt disease was evaluated in vivo. Disease severity and growth markers were recorded and in vitro antagonistic activity assay of the isolated A. fumigatus and R. oryzae against Fusarium oxysporum was measured. Physiological markers of defense in plant as response to stimulate systemic resistance (SR) were recorded. Our results indicated that A. fumigatus and R. oryzae decreased the percentage of disease severity by 12.5 and 37.5%, respectively. In addition, they exhibited relatively high protection percentage of 86.35 and 59.06% respectively. Fusarium wilt was declined the growth parameters, photosynthetic pigments, total soluble carbohydrate, and total soluble protein, whereas content of free proline, total phenols, and the activity of antioxidant enzymes activity increased under infection. Moreover, application of A. fumigatus and R. oryzae on infected plants successfully recovered the loss of morphological traits, photosynthetic pigment total carbohydrates, and total soluble proteins in comparison to infected control plants. PGPF strains in both non-infected and infected plants showed several responses in number and density of peroxidase (POD) and polyphenol oxidase (PPO) isozymes.

Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Zea mays L. Using Endophytic Aspergillus fumigatus

Aspergillus flavus infection of vegetative tissues can affect the development and integrity of the plant and poses dangerous risks on human and animal health. Thus, safe and easily applied approaches are employed to inhibit A. flavus growth. To this end, the fungal endophyte, i.e., Aspergillus fumigatus, was used as a safe biocontrol agent to reduce the growth of A. flavus and its infection in maize seedlings. Interestingly, the safe endophytic A. fumigatus exhibited antifungal activity (e.g., 77% of growth inhibition) against A. flavus. It also reduced the creation of aflatoxins, particularly aflatoxin B₁ (AFB₁, 90.9%). At plant level, maize seedling growth, leaves and root anatomy and the changes in redox status were estimated. Infected seeds treated with A. fumigatus significantly improved the germination rate by 88.53%. The ultrastructure of the infected leaves showed severe disturbances in the internal structures, such as lack of differentiation in cells, cracking, and lysis in the cell wall and destruction in the nucleus semi-lysis of chloroplasts. Ultrastructure observations indicated that A. fumigatus treatment increased maize (leaf and root) cell wall thickness that consequentially reduced the invasion of the pathogenic A. flavus. It was also interesting that the infected seedlings recovered after being treated with A. fumigatus, as it was observed in growth characteristics and photosynthetic pigments. Moreover, infected maize plants showed increased oxidative stress (lipid peroxidation and H₂O₂), which was significantly mitigated by A. fumigatus treatment. This mitigation was at least partially explained by inducing the antioxidant defense system, i.e., increased phenols and proline levels (23.3 and 31.17%, respectively) and POD, PPO, SOD and CAT enzymes activity (29.50, 57.58, 32.14 and 29.52%, respectively). Overall, our study suggests that endophytic A. fumigatus treatment could be commercially used for the safe control of aflatoxins production and for inducing biotic stress tolerance of A. flavus-infected maize plants.

Ecofriendly Synthesis of Biosynthesized Copper Nanoparticles with Starch-Based Nanocomposite: Antimicrobial, Antioxidant, and Anticancer Activities

In recent years, polysaccharides-based nanocomposites have been used for biomedical applications. In the current study, a nanocomposite based on myco-synthesized copper nanoparticles (CuNPs) and starch was prepared. The prepared nanocomposite was fully characterized using UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), mapping, transmission electron microscope (TEM), and dynamic light scattering (DLS). Results revealed that this nanocomposite is characterized by nano spherical shape ranged around 200 nm as well as doped with CuNPs with size about 9 nm. Antimicrobial, antioxidant, and anticancer activities of the prepared nanocomposite were evaluated. Results revealed that CuNPs-based nanocomposite exhibited outstanding antibacterial and antifungal activity toward Escherichia coli ATCC25922, Bacillus subtilis ATCC605, Candida albicans ATCC90028, Cryptococcus neoformance ATCC 14,116, Aspergillus niger RCMB 02,724, A. terreus RCMB 02,574, and A. fumigatus RCMB 02,568. Moreover, CuNPs-based nanocomposite has a strong antioxidant activity as compared to ascorbic acid, where IC₅₀ was 18 µg/mL. Cytotoxicity test of CuNPs-based nanocomposite revealed that this nanocomposite is safe in use, where IC₅₀ was 185.1 µg/mL. Furthermore, CuNPs-based nanocomposite exhibited potential anticancer activity against MCF7 cancerous cell line where IC₅₀ was 62.8 µg/mL which was better than CuNPs alone. In conclusion, the prepared CuNPs with starch-based nanocomposite is promising for different biomedical applications as antimicrobial, antioxidant, and anticancer activities.

Potential of biosynthesized zinc oxide nanoparticles to control Fusarium wilt disease in eggplant (Solanum melongena) and promote plant growth

In this study, a novel, non-toxic, eco-friendly zinc oxide nanoparticles (ZnO-NPs) was used instead of the synthetic fungicides widely used to control the destructive phytopathogenic fungus Fusarium oxysporum, the causative agent of wilt disease in Solanum melongena L. Herein, the biosynthesized ZnO-NPs was carried out by Penicillium expansum ATCC 7861. In vitro, mycosynthesized ZnO-NPs exhibited antifungal activity against Fusarium oxysporum. In vivo, ZnO-NPs suppressed Fusarium wilt disease in cultivated Solanum melongena L. by decreasing the disease severity with 75% of plant protection. Moreover, ZnO-NPs stimulated the recovery of eggplant as an indicated by improving of morphological and metabolic indicators including plant height(152.5%), root length(106.6%), plant fresh biomass (146%), chlorophyll a (102.8%), chlorophyll b (67.86%), total soluble carbohydrates (48.5%), total soluble protein (81.8%), phenol (10.5%), antioxidant activity and isozymes compared with infected control. Therefore, this study suggests using mycosynthesized ZnO-NPs as an alternative to synthetic fungicides not only to eradicate the Fusarium wilt disease in cultivated eggplant (Solanum melongena) but also to promote the growth parameters and metabolic aspects.

Current state of the art biotechnological strategies for conversion of watermelon wastes residues to biopolymers production: A review

Poly-3-hydroxyalkanoates (PHA) are biodegradable and compostable polyesters. This review is aimed to provide a unique approach that can help think tanks to frame strategies aiming for clean technology by utilizing cutting edge biotechnological advances to convert fruit and vegetable waste to biopolymer. A PHA manufacturing method based on watermelon waste residue that does not require extensive pretreatment provides a more environmentally friendly and sustainable approach that utilizes an agricultural waste stream. Incorporating fruit processing industry by-products and water, and other resource conservation methods would not only make the manufacturing of microbial bio-plastics like PHA more eco-friendly, but will also help our sector transition to a bioeconomy with circular product streams. The final and most critical element of this review is an in-depth examination of the several hazards inherent in PHA manufacturing.

Green and ecofriendly biosynthesis of selenium nanoparticles using Urtica dioica (stinging nettle) leaf extract: Antimicrobial and anticancer activity

BACKGROUND/GOAL/AIM

Plant extract is affordable and does not require any particular conditions; rapid production of nanoparticles using plants offers more advantages than other approaches. Selenium nanoparticles (SeNPs) have received much attention in the last decade due to SeNPs diverse and different applications. Herein, this study aimed to biosynthesize SeNPs using aqueous extract of Urtica dioica leaf through green and ecofriendly method. Moreover to fully characterize SeNPs using different techniques, and to evaluate it for antimicrobial activity as well as anticancer activity.

MAIN METHODS AND MAJOR RESULTS

SeNPs were biosynthesis using aqueous leaf extract of U. dioica (stinging nettle). The biosynthesized SeNPs were characterized using UV-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive electron spectroscopy (EDX), transmission electron microscopy (TEM), and thermal-gravimetric analysis (TGA). Antimicrobial and anticancer activities of biosynthesized SeNPs were assessed. Results illustrated that SeNPs exhibited promising antibacterial activity against Gram-positive and Gram-negative bacteria, as well as unicellular and multi-cellular fungi. Moreover, minimal-inhibitory concentration (MIC) of SeNPs against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus were 250, 31.25, and 500 μg mL^-1 , respectively, while were 62.5, 15.62, 31.25, and 7.81 μg mL^-1 against Candida albicans, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus, respectively. The cytotoxicity of SeNPs was performed on Vero normal-cell line CCL-81, where IC₅₀ was 173.2 μg mL^-1 .

CONCLUSIONS AND IMPLICATIONS

For the first time, aqueous stinging nettle leaf extract was utilized to biosynthesize SeNPs in a green method. SeNPs have outstanding antimicrobial-activity against pathogenic bacterial and fungal strains. Moreover, SeNPs have promising anticancer activity against HepG2 cancerous cell line without cytotoxicity on Vero normal cell line. Finally, the biosynthesized SeNPs via aqueous extract of stinging nettle leaf exhibited potential antibacterial, antifungal, and anticancer action, making them useful in the medical field.

Antimicrobial and antiviral activities with molecular docking study of chitosan/carrageenan@clove oil beads

BACKGROUND

Biopolymers are promising candidates that can be fabricated into hydrophilic matrices and used for many applications due to their distinctive properties such as non-toxic, biodegradable, biocompatibility, and low cost. A promising composite of chitosan and carrageenan with self-crosslinking has been prepared.

METHODS AND RESULTS

In this study, a rigorous approach for an inexpensive and non-toxic combination of different amounts of clove oil with two polyelectrolytes including chitosan and carrageenan in the form of beads have been prepared. The structure and the surface morphology of the beads were investigated using FTIR, XRD, and SEM. Moreover, antimicrobial, antiviral activity, and molecular docking were evaluated. Antibacterial results revealed that chitosan/carrageenan@clove oil beads have antimicrobial activity as well as chitosan/carrageenan without clove oil against Escherichia colia ATCC25922, Pseudomonas aeruginosa aATCC27853, Staphylococcus aureus ATCC25923, Bacillus subtilisaATCC6051 and Candida albicanssATCC90028. Furthermore, maximum non-toxic concentration (MNTC) of chitosan/carrageenan@clove oil beads was (31.25 μg/mL) which exhibited promising antiviral activity against Herpes simplex virus-1 (HSV-1), and was significantly higher than chitosan/carrageenan without clove oil, where antiviral activity was 82.94 and 57.64% respectively. Eventually, docking study and computational calculation have been used to show the reactivity of the molecules.

CONCLUSIONS

The developed chitosan/carrageenan@clove oil beads have shown promising properties to be used as carriers of drug delivery, tissue engineering, and regenerative medicine. This article is protected by copyright. All rights reserved.

Antimicrobial, Antioxidant, Cytotoxic Activities and Phytochemical Analysis of Fungal Endophytes Isolated from Ocimum Basilicum

Fungal endophytes are living inside plants without any harmful effects; the prospecting about them is increased day by day because they can produce bioactive compounds which can be used in different applications. Herein, the current study was aimed to isolate the endophytic fungi from the Ocimum basilicum plant as safe microorganisms and evaluate their biological activities. The results illustrated that three endophytic fungal strains were isolated and identified morphologically and genetically as Aspergillus nidulans, Aspergillus fumigatus, and Aspergillus flavus and deposited in gene bank under accession numbers MZ045561, MZ045562, and MZ045563 respectively. Moreover, cell-free filtrates of endophytic fungal strains were extracted using ethyl acetate, where these crude extracts exhibited promising antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumonia, and Candida albicans at a concentration of 1000 µg/mL. Furthermore, these endophytic strains exhibited a potential antioxidant activity where IC₅₀ of the crude extract of A. nidulans, A. fumigatus, and A. flavus were (166.3, 68.4, and 347.1 µg/mL) and (151.2, 77.9, and 246.3 µg/mL) using DPPH and ABTS methods, respectively. Furthermore, the ethyl acetate crude extracts of these endophytic fungi did not exhibit any cytotoxic effect against Vero and Wi 38 normal cells. GC-MS analysis of the crude extract of A. nidulans, A. fumigatus, and A. flavus indicated the presence of 22, 22, and 20 active compounds, respectively. The major compounds in the fungal extracts are belonging to fatty acids, fatty acid esters, tetrahydrofurans, and sterols. In conclusion, the isolated endophytic A. nidulans, A. fumigatus, and A. flavus from Ocimum basilicum are promising sources for bioactive compounds.

Ecofriendly preparation of silver nanoparticles-based nanocomposite stabilized by polysaccharides with antibacterial, antifungal and antiviral activities

In the present work, sustainable and green method was used to prepare silver nanoparticles (Ag-NPs), followed with incorporation into tertiary nanocomposite consisted of starch, oxidized cellulose and ethyl cellulose. The prepared tertiary silver-nanocomposite (Ag-NC) was fully characterized via instrumental analysis (UV-vis, FT-IR, XRD, SEM, EDX and TEM) and evaluated for antibacterial, antifungal, and antiviral activities. Ag-NC significantly suppressed growth of tested bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis)  as compared with controls. Antifungal activity revealed that the prepared tertiary Ag-NC has a promising antifungal activity towards unicellular (Candida albicans) and multicellular fungi  ( Aspergillus niger, A. terreus, A. flavus and A. fumigatus). In same line, both Ag-NC and free Ag-NPs have shown a dose-dependent reduction in Vero cell line with maximum non-toxic dose at 6.25 and 12.5 μg/mL, respectively. Both Ag-NPs and Ag-NC exhibited antiviral effects against Herpes simplex virus, Adenovirus and Coxsackie B virus in a dose-dependent manner. Combined treatment of Ag-NPs incorporated into tertiary nanocomposite based on starch, oxidized cellulose and ethyl cellulose opens new possibilities to be more efficient nanomaterials for preventing microbial growth. In conclusion, the prepared tertiary Ag-NC has a promising antibacterial, antifungal as well as antiviral activities.

Antimicrobial and Antiviral Activities of Durable Cotton Fabrics Treated with Nanocomposite Based on Zinc Oxide Nanoparticles, Acyclovir, Nanochitosan, and Clove Oil

In this study, cotton fabrics based on zinc oxide nanoparticles in situ synthesis, acyclovir, nanochitosan, and clove oil were treated. The treated cotton fabrics were examined by FTIR, HR-TEM, FE-SEM, EDAX, and the surface roughness processing of FE-SEM images. The obtained characterization data emphasized the nano-size of nanocomposite with high homogeneity of particles in spherical shape as well as affirmed the deposition of nanocomposite onto the textile fibers with concluded that the deposition of nanocomposite was increased parallel with sonication time. Antimicrobial and antiviral activities of treated cotton fabrics were evaluated. Results revealed that treated cotton fabrics exhibited promising antibacterial activity toward Gram-positive higher than Gram-negative bacteria. Likewise, treated cotton fabrics are still effective as antibacterial after washing for 100 cycles. Moreover, treated cotton fabrics exhibited potential antifungal activity against Candida albicans, Aspergillus niger, and Aspergillus fumigatus. The antiviral activity significantly depended on the type of virus. The treated cotton fabrics showed antiviral activity against tested viral particles (HSV-1, Adeno, and CoxB2) with viral inhibition of 95.9, 76.4, and 86.9% respectively, while in the case of coated cotton textile with acyclovir, it only exhibited viral inhibition of 49.9, 41, and 22.3% respectively.

Bacillus megaterium-Mediated Synthesis of Selenium Nanoparticles and Their Antifungal Activity against Rhizoctonia solani in Faba Bean Plants

Rhizoctonia root-rot disease causes severe economic losses in a wide range of crops, including Vicia faba worldwide. Currently, biosynthesized nanoparticles have become super-growth promoters as well as antifungal agents. In this study, biosynthesized selenium nanoparticles (Se-NPs) have been examined as growth promoters as well as antifungal agents against Rhizoctonia solani RCMB 031001 in vitro and in vivo. Se-NPs were synthesized biologically by Bacillus megaterium ATCC 55000 and characterized by using UV-Vis spectroscopy, XRD, dynamic light scattering (DLS), and transmission electron microscopy (TEM) imaging. TEM and DLS images showed that Se-NPs are mono-dispersed spheres with a mean diameter of 41.2 nm. Se-NPs improved healthy Vicia faba cv. Giza 716 seed germination, morphological, metabolic indicators, and yield. Furthermore, Se-NPs exhibited influential antifungal activity against R. solani in vitro as well as in vivo. Results revealed that minimum inhibition and minimum fungicidal concentrations of Se-NPs were 0.0625 and 1 mM, respectively. Moreover, Se-NPs were able to decrease the pre-and post-emergence of R. solani damping-off and minimize the severity of root rot disease. The most effective treatment method is found when soaking and spraying were used with each other followed by spraying and then soaking individually. Likewise, Se-NPs improve morphological and metabolic indicators and yield significantly compared with infected control. In conclusion, biosynthesized Se-NPs by B. megaterium ATCC 55000 are a promising and effective agent against R. solani damping-off and root rot diseases in Vicia faba as well as plant growth inducer.

Ecofriendly novel synthesis of tertiary composite based on cellulose and myco-synthesized selenium nanoparticles: Characterization, antibiofilm and biocompatibility

Microbial infections are considered common and dangerous for humans among other infections; therefore the synthesis of high efficacy antimicrobial and anti-biofilm composites is continuous to fight microbial resistance. In our study, a new and novel tertiary composite (TC) was synthesized, it composed of TEMPO cellulose (TOC), chitosan, starch, and myco-synthesized Se-NPs. Myco-synthesized Se-NPs and TC were fully characterized using UV, FT-IR, XRD, SEM with EDX, particle distribution, and mapping. The antimicrobial and anti-biofilm properties of selenium nanoparticles (Se-NPs) were effectively established for Pseudomonas aeruginosa and Staphylococcus aureus biofilms. The possible impact of myco-synthesized novel cellulose-based selenium nanoparticles tertiary composite on the biofilm formation of P. aeruginosa, S. aureus, and Candida albicans was evaluated in this study. TC exhibited constant biofilm inhibition against P. aeruginosa, S. aureus, and C. albicans, while the results obtained from cytotoxicity of Se-NPs and TC showed that, alteration occurred in the normal cell line of lung fibroblast cells (Wi-38) was shown as loss of their typical cell shape, granulation, loss of monolayer, shrinking or rounding of Wi-38 cell with an IC₅₀ value of where 461 and 550 ppm respectively.

Fungal endophytes from leaves of Avicennia marina growing in semi-arid environment as a promising source for bioactive compounds

Endophytic fungi are broadly dispersed residing inside plant tissues and have been demonstrated as a treasure for bioactive natural products. Unexplored harsh and heavy metal contaminant habitat of Avicennia marina may have diverse and potential fungal association. Therefore, this work aimed to isolate the culturable fungal endophytes associated with leaves of A. marina and to evaluate their medical potentialities. Seventeen isolates of endophyte fungi were isolated from healthy leaves and their antimicrobial activities were evaluated. Results showed that isolates had activity against micro-organisms in addition to their antioxidant activity produced a variety of phenolic compounds, besides exhibited a lowest cytotoxicity against ATCC-CCL-81 cell line. Consequently, selected endophytic fungal isolates were identified genetically as Chaetomium sp., Chaetomium madrasense, Chaetomium sp., Chaetomium globosum, Aspergillus hiratsukae, Aspergillus ochraceus, Alternaria tenuissima and Curvularia lunata with gene bank accession numbers MT089951, MT089952, MT089953, MT089954, MT089955, MT089956, MT089957 and MT089958 respectively. The most potent fungus extract was analysed using Gas chromatography-mass spectrometry which verified the presence of numerous bioactive compounds. These findings confirmed that new endophytic fungal strains derived from A. marina thrive in harsh ecosystem produce bioactive metabolites which can be recommended as a novel source for drug discovery.