P.Ponmurugan*, Jyoti Prasad Kakati, R.Subbaiya and J.Philip Robinson

Department of Biotechnology, K.S.Rangasamy College of Technology

Tiruchengode - 637 215, Namakkal District, Tamil Nadu, India.

E-mail: drponmurugan@gmail.com

Abstract

Ecofriently generated silver and gold nanoparticles, known as nanocrystallins, are widely employed in the management of numerous pathogenic bacteria that affect humans, animals, and plants. In light of this, an assessment was conducted to determine whether the suppressive capability of nanoparticles generated by the native isolate Trichoderma atroviride against the fungal pathogen Pythium aphanidermatum, which causes turmeric, could be achieved. Spectrophotometric measurements were made at various wavelengths within the range of 300-700 nm to quantify the gold and silver , Using TSM medium supplemented with an aqueous solution containing 2x10-3 M chloroauric acid and 3x10-4 M silver nitrate, T. atroviride generated nanoparticles. The creation of gold and silver nanoparticles was found to have two strong peaks at 450 and 410 nm, respectively, according to the UV-VIS spectra measurements. Even after two months, it was discovered that these peaks remained rather steady, which was consistent with the stability of nanoparticle formation. The antibiotic activity between T. atroviride and P. aphanidermatum was investigated using the culture filtrate that contained nanoparticles. The findings showed that P. aphanidermatum's growth might be inhibited by the culture filtrate.

Introduction

It is becoming clear that using microbes to synthesise nanoparticles is an innovative and environmentally beneficial method. A study that involved screening Rhodo-pseudomonas cappsulata revealed that the bacterium was capable of producing gold and silver nanoparticles with varying sizes and shapes. Therefore, it is crucial to synthesise these nanoparticles in a variety of sizes and shapes for use in the management of plant diseases. An earlier study discovered that inside the cell walls of Bacillus subtilis, Au3+ ions could be reduced to gold nanoparticles with a size range of 5–25 nm. With the use of hydrogen gas, Shewanella globrella alga was discovered to reduce Au3+ ions, generating 10–20 nm gold nanoparticles extracellularly [1]. Nanopartocles were also synthesised intra- and extracellularly using fungi like Verticillium lecanni and Fusarium oxysporum and actinomycetes like Streptomyces, Thermomonospora, and Rhodococus spp. [2]. Silver and gold nanoparticle biosynthesis is still rare, nevertheless. Trichoderma atroviride, a Eukaryote fungus, is identified in this study as one of the ecologically and environmentally significant biocontrol agents frequently employed to control a variety of plant diseases.

Curcuma longa L., a member of the Zingiberaceae family, is a widely grown commercial spice crop in India. When it comes to quality and lack of illness, Indian turmeric is regarded as the best in the world [3]. In southern India's Andhra Pradesh, Karnataka, Kerala, and Tamil Nadu states, Pythium aphanidermatum-caused rhizome rot disease is a major issue for turmeric plantations, and since 2006, the illness has significantly decreased turmeric exports [4]. Soil drenching is recommended as a means of controlling the disease, with contact fungicides such as Mancozeb and systemic fungicides like Carbendazim [5]. Fungicide-soaked soil has an adverse effect on healthy microorganisms as well as the soil itself. Antagonists of bacteria, fungi, and actinomycete species have been used to effectively control a wide range of plant diseases [6, 7]. Nevertheless, there is no evidence on the use of culture filtrate containing Trichoderma atroviride nanoparticles for the biological control of turmeric rhizome rot disease.

Conclusions

In summary, Trichoderma atroviride was able to produce silver and gold nanoparticles in addition to TSM medium, an antibiotic, to combat the fungal infection Pythium aphanidermatum, which is associated with turmeric. To initiate the creation of silver and gold nanoparticles, TSM medium was supplemented with silver nitrate and chloroauric acid, respectively. Spectroscopy was used to measure them at different wavelengths, and two prominent peaks were discovered that correlated with the creation of gold and silver nanoparticles. To demonstrate the stability of the nanoparticles followed by the pathogen's antagonistic activity, these peaks were observed to be quite stable for two to three months. The inclusion of gold and silver nanoparticles in the culture filtrate hindered P. aphanidermatum's in vitro growth.

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