Biosynthesis has emerged as a frontier technology for fabrication of functionally diverse nanoparticles that possess tremendous therapeutic implications. Various biological resources have already demonstrated their potential to produce nanoparticles with interesting features. Endophytic microbes live in a symbiotic relationship with plants possessing a unique and versatile reservoir of potentially therapeutic secondary metabolites having the tendency to reduce metallic ions into nanoparticles. Successful biosynthesis of AgNPs using endophytic organisms has already been reported; however, the overall picture about its synthesis and applications is still not clear. In the current article, a comprehensive review of literature was performed for comparing different physical and biological properties of endophytic microbe-derived AgNPs. In addition, the present paper mechanistically explains the synthesis of AgNPs and their diverse pharmacognostic properties. Further studies are encouraged to understand the mechanism of biopharmaceutical effects of these endophyte-mediated NPs.

Endophyte-mediated synthesis of silver nanoparticles and their biological applications

Nanotechnology is a promising field as wide range of research is ongoing in this field throughout the world. Nanotechnology has revolutionized the agronomy system with the development of new tools. Nanotechnology provides a stage for the development of the essential characteristics of metal in the form of nanoparticles (NPs) having promising use in diagnostics, biomarkers, cell labeling, antimicrobial agents, nano-drugs, etc. for treatment of various disease. The synthesis of NPs by chemical and physical methods is extremely costly and utilizing toxic or hazardous chemicals for their formulation which causes threat to ecosystem. In the present time, there is need to develop NPs which are eco-friendly and cost effective. It is well known that biological entities like microorganisms and living cells are the example of machines that possess operating parts at the nanoscale and performing their action with very high efficiency. Endophytes are microorganisms (bacteria and fungi) that are present in living tissue of various plants like root, fruit, stem, seed, leaf, etc. establishing mutual relationship without apparently any symptoms of diseases. The plants are known to harbor endophytic microbes that are believed to be associated with the production of pharmaceutical products. The microbes have a number of advantages for green synthesis of NPs. The use of microbes for the synthesis of NPs could be more advantageous, because of the tolerance, bioaccumulation, and extracellular production of enzymes at large scale. Therefore, synthesis of NPs from microbes is a boon for advance research in nanotechnology.

Endophytic microbes in nanotechnology: Current development, and potential biotechnology applications

Emerging antibiotic-resistant bacteria result in increased mortality and have negative economic impacts. It is necessary to discover new strategies to create alternative antibacterial agents that suppress the bacterial resistance mechanism and limit the spread of serious infectious bacterial diseases. Silver nanoparticles may represent a new medicinal agents as alternative antibiotics affect different bacterial mechanisms such as virulence and resistance. In addition to that of silver nitrate (AgNO3) and ampicillin, for the first time, the inhibitory effect of silver nanoparticles synthesized using Desertifilum sp. (D-SNPs) was evaluated against five pathogenic bacteria using the agar well diffusion method. Also, the influence of D-SNPs and AgNO3 on bacterial antioxidant and metabolic activities was studied. The antibacterial activity of D-SNPs and AgNO3 against methicillin-resistant Staphylococcus aureus (MRSA) strains was studied at the morphological and molecular level. D-SNPs and AgNO3 have the ability to inhibit the growth of the five bacterial strains and resulted in an imbalance in the CAT, GSH, GPx and ATPase levels. MRSA treated with D-SNPs and AgNO3 showed different morphological changes such as apoptotic bodies formation and cell wall damage. Moreover, both caused genotoxicity and denaturation of MRSA cellular proteins. Additionally, TEM micrographs showed the distribution of SNPs synthesized by MRSA. This result shows the ability of MRSA to reduce silver nitrate into silver nanoparticles. These data indicate that D-SNPs may be a significant alternative antibacterial agent against different bacteria, especially MDR bacteria, by targeting the virulence mechanism and biofilm formation, leading to bacterial death.

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Novel Biogenic Silver Nanoparticle-Induced Reactive Oxygen Species Inhibit the Biofilm Formation and Virulence Activities of Methicillin-Resistant Staphylococcus aureus (MRSA) Strain.

The present study was carried out to synthesize silver nanoparticles (AgNPs) using extracts of wild edible mushroom, Pleurotus giganteus, and to characterize the synthesized AgNPs and also to evaluate the synthesized AgNPs for antimicrobial and α-amylase inhibitory activity. Green synthesized AgNPs were characterized by UV–Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, Atomic force microscopy (AFM), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), selected area electron diffraction (SAED), Energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Antibacterial activity of AgNPs was studied by disc diffusion method along with minimum inhibitory concentration (MIC) and α-amylase inhibition assay of AgNPs were also studied. UV–Vis spectra of reaction mixture of AgNPs exhibited surface plasmon resonance peak around at 420 nm. FTIR study revealed that mainly carboxyl, hydroxyl, and amine functional groups were present in a mushroom extract which mainly reduced Ag+ to Ag0. AFM, TEM, SEM, SAED, and XRD pattern analysis supported that synthesized AgNPs were mostly spherical shaped within average size 2–20 nm and crystalline in nature. Biosynthesized AgNPs showed more antibacterial potentiality against Gram (–) bacteria. MIC of green synthesized AgNPs were found against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus as 12, 10, 14, and 15 μg/ml, respectively. α-Amylase inhibition assay of green synthesized AgNPs revealed that percent inhibition of α-amylase decreased with increasing concentration of green synthesized AgNPs. Wild edible mushroom P. giganteus can be used as a source of reducing and capping agents of spherical metallic silver nanoparticles which offers potential medicinal properties.

Green Synthesis of Silver Nanoparticles Using Mushroom Extract of Pleurotus giganteus: Characterization, Antimicrobial, and α-Amylase Inhibitory Activity

The oyster mushroom (Pleurotus sp.) is one of the most important edible and medicinal mushrooms because it contains a variety of effective compounds. In recent years, metallic nanoparticles, especially silver nanoparticles (AgNPs), have been produced in a green method from different organic matters of fungi especially Pleurotus sp. The oyster mushroom occupied first among macrofungi in the production of nanoparticles and their applications. AgNPs were the most common among the other types of metallic nanoparticles which synthesized from this mushroom. Properties of these AgNPs showed spherical particles with crystalline nature and average sizes ranged from 2 to 100 nm. AgNPs also exhibited inhibitory effects against many pathogenic bacteria, fungi, and yeasts as well as cancer and was used to remove textile dyes. The importance of this mushroom is coming from the quantity and size of the produced fruit bodies and their bioactive materials which used as natural precursors to reduce silver ions into Ag atoms. P. ostreatus, P. florida, and P. sajor caju are the most widely used in the synthesis of AgNPs respectively and there are more than 70 other species that have not been studied in this regard. This is the first review to discuss the production of nano-silver of different species of oyster mushroom for more than ten years from 2007 to 2019 because they are new studies in the field of nanotechnology. This green production is non-toxic, cheap, easily-forming and eco-friendly and has many future prospects in the application on various medical and industrial fields.

Green synthesis of silver nanoparticles by Pleurotus (oyster mushroom) and their bioactivity: Review

The aim of the present study was to test the efficacy of the extracellular mycelium extract of Penicillium oxalicum isolated from Phlogacanthus thyrsiflorus to biosynthesize silver nanoparticles. It was characterized using ultraviolet–visible absorption spectroscopy, atomic force microscopy, transmission electron microscopy and Fourier transforms infrared spectroscopy. The silver nanoparticles were evaluated for antimicrobial activity. The characterization confirms the synthesis of silver nanoparticles. Both silver nanoparticles and combination of silver nanoparticles with streptomycin showed activity against the four bacteria. The results suggested that P. oxalicum offers eco-friendly production of silver nanoparticles and the antibacterial activity may find application in biomedicine.

https://iopscience.iop.org/article/10.1088/2043-6254/aa84ec/pdf

Characterization of silver nanoparticles synthesized using an endophytic fungus, Penicillium oxalicum having potential antimicrobial activity

The present investigation was conducted to synthesize and characterize silver nanoparticles using wild edible mushroom extract of Lentinus tuber-regium. The current investigation also aims to determine antimicrobial and α-amylase inhibitory activity of biosynthesized silver nanoparticles (AgNPs). UV–Visible spectrophotometer study indicated that the surface plasmon resonance peak of reaction of AgNPs was around at 433 nm which confirmed the formation of AgNPs. Fourier-transform infrared spectroscopy analysis confirms that carboxyl functional groups in mushroom extract are mainly responsible in reduction of Ag+ ions to Ag0 nanoparticles. Atomic force microscopy, transmission electron microscopy and scanning electron microscopy analysis revealed that synthesized AgNPs were spherical and have an average size within 5 to 35 nm. Selected area electron diffraction and X-ray diffraction pattern displayed that synthesized AgNPs were crystalline in nature. Energy-dispersive X-ray spectroscopy study showed 10.50% of silver metal in weight in the sample. Biosynthesized AgNPs showed more antibacterial activity in Gram (−) bacteria than Gram (+). Minimum inhibitory concentration values of the biosynthesized AgNPs against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus subtilis were found to be 9, 12, 14 and 13 µg/ml, respectively. Inhibition of α-amylase activity increased with increasing concentration of biosynthesized AgNPs. This work substantially indicates that mushroom is efficient in biosynthesis of silver nanoparticles having potential antimicrobial and α-amylase inhibitory activity.

Characterization, Antimicrobial and α-Amylase Inhibitory Activity of Silver Nanoparticles Synthesized by using Mushroom Extract of Lentinus tuber - regium

This study was aimed to evaluate the allelopathic effect of the aqueous leaf extract of Clerodendrum infortunatum L. on seed germination, plumule and radicle growth of some agricultural crops such as Triticum aestivum L. (Wheat), Brassica campestris (Mustard), Vigna radiata (L) R.wilczek (Mung bean) and Trigonella foenum-graecum L. (Methi). The ground leaves of C. infortunatum were mixed with distilled water in 1:10 ratio and used as stock solution. The inhibitory effect was studied at 25%, 50% and 75% of aqueous solution and distilled water (control). It was found that the aqueous leaf extract C. infortunatum had inhibitory effect on germination, plumule and radical elongation of tested crops. The results revealed that the inhibitory effect was much more pronounced at higher extract concentrations showing allelopathic potential which may be exploited in controlling seed germination and seedling growth of crops.

http://www.irjponline.com/admin/php/uploads/2614_pdf.pdf

Allelopathic effect of clerodendrum infortunatum l. leaf extract on seed germination and seedling growth of some agricultural crops of tripura, india

Cellulase is a class of enzyme that has great industrial importance. Cellulase catalyzes the hydrolysis of 1, 4 β-D glycosidic linkages in cellulose are mainly produced from a wide variety of microorganisms like fungi, bacteria and protozoan. The present study aimed at the screening and production of extracellular cellulase enzyme produced by a wild edible mushroom Pleurotus giganteus. Different physical and chemical parameters such as temperature, pH, substrate concentration and reaction time on cellulase activity were also studied. The clear yellowish zone around mycelial plug revealed that screening of extracellular cellulase activity of P. giganteus was positive. Cellulase production by using the mushroom was highest after 6 days of the incubation period. Extracellular cellulase activity was maximum at 50 o C temperature, pH 5, 1.4% of substrate concentration (Carboxy-methylcellulose) and 30 minutes of reaction time. The present investigation revealed that wild edible mushroom P. giganteus may be utilized as a source for the production of industrial cellulase.

http://nopr.niscair.res.in/bitstream/123456789/53485/1/IJNPR%2010%283%29%20195-199.pdf

Gopal Debnath

Papers

Green Synthesis of Silver Nanoparticles Using Mushroom Extract of Pleurotus giganteus: Characterization, Antimicrobial, and α-Amylase Inhibitory Activity

Characterization of silver nanoparticles synthesized using an endophytic fungus, Penicillium oxalicum having potential antimicrobial activity

Characterization, Antimicrobial and α-Amylase Inhibitory Activity of Silver Nanoparticles Synthesized by using Mushroom Extract of Lentinus tuber - regium

Allelopathic effect of clerodendrum infortunatum l. leaf extract on seed germination and seedling growth of some agricultural crops of tripura, india

Screening and characterization of extracellular cellulase enzyme produced by wild edible mushroom Pleurotus giganteus