Ameliorated Antibacterial and Antioxidant Properties by Trichoderma harzianum Mediated Green Synthesis of Silver Nanoparticles.

Narasimhamurthy Konappa,Savitha De Britto,Chamanahalli Kyathegowda Pradeep,Srinivas Chowdappa,Sudisha Jogaiah,Shubha Jagannath,Nirmaladevi Dhamodaran,Soumya Krishnamurthy,Savitha De Britto,Arakere C Udayashankar,Fazilath Uzma

doi:10.3390/biom11040535

Abstract

Biosynthesis of silver nanoparticles using beneficial Trichoderma harzianum is a simple, eco-friendly and cost-effective route. Secondary metabolites secreted by T. harzianum act as capping and reducing agents that can offer constancy and can contribute to biological activity. The present study aimed to synthesize silver nanoparticles using T. harzianum cell filtrate and investigate different bioactive metabolites based on LC-MS/MS analysis. The synthesized silver nanoparticles (AgNPs) from T. harzianum were characterized by ultraviolet–visible spectrophotometry, Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The surface plasmon resonance of synthesized particles formed a peak centered near 438 nm. The DLS study determined the average size of AgNPs to be 21.49 nm. The average size of AgNPs was measured to be 72 nm by SEM. The cubic crystal structure from XRD analysis confirmed the synthesized particles as silver nanoparticles. The AgNPs exhibited remarkable antioxidant properties, as determined by DPPH and ferric reducing antioxidant power (FRAP) assay. The AgNPs also exhibited broad-spectrum antibacterial activity against two Gram-positive bacteria (S. aureus and B. subtilis) and two Gram-negative bacteria (E. coli and R. solanacearum). The minimum inhibitory concentration (MIC) of AgNPs towards bacterial growth was evaluated. The antibacterial activity of AgNPs was further confirmed by fluorescence microscopy and SEM analysis.

Highlights

Nanotechnology has evolved as an interesting part of research because of its ability to produce nanoparticles (NPs) possessing uniformity and special properties that make them valuable in optical sensors, drug delivery, catalysis, adsorption, water treatment and nanomedicine [1]
The LC-MS/MS spectra of the filtrate showed the presence of five different compounds with varied mass obtained at different retention times (Figure 1B–D)
The compounds were tentatively identified based on the mass obtained from LC-MS/MS by comparison with the previously reported compounds documented in databases

Summary

Introduction

Nanotechnology has evolved as an interesting part of research because of its ability to produce nanoparticles (NPs) possessing uniformity and special properties that make them valuable in optical sensors, drug delivery, catalysis, adsorption, water treatment and nanomedicine [1]. These NPs can be produced from different chemical, physical. Biomolecules 2021, 11, 535 and biological processes. Electrochemical and pyrolysis-based methods for the production of NPs are toxic, non-eco-friendly and difficult to perform. The requirement of strong reducing agents and toxic chemicals such as borohydride and hydrazine derivatives can increase the cost of production and result in hazardous wastes being released into the environment [2]

Methods

Results

Discussion

Conclusion