Bacteria assisted green synthesis of copper oxide nanoparticles and their potential applications as antimicrobial agents and plant growth stimulants

Deepak Singh; Devendra Jain; Deepak Rajpurohit; Gajanand Jat; Himmat Singh Kushwaha; Abhijeet Singh; Santosh Ranjan Mohanty; Mohammad Khalid Al-Sadoon; Wajid Zaman; Sudhir K Upadhyay

doi:10.3389/fchem.2023.1154128

Bacteria assisted green synthesis of copper oxide nanoparticles and their potential applications as antimicrobial agents and plant growth stimulants

Front Chem. 2023 Apr 7:11:1154128. doi: 10.3389/fchem.2023.1154128. eCollection 2023.

Affiliations

¹ Department of Molecular Biology and Biotechnology, Maharana Pratap University of Agriculture and Technology, Udaipur, India.
² Department of Soil Science and Agricultural Chemistry, Maharana Pratap University of Agriculture and Technology, Udaipur, India.
³ Material Research Centre, Malviya National Institute of Technology, Jaipur, India.
⁴ Department of Biosciences, Manipal University Jaipur, Jaipur, India.
⁵ All India Network Project on Soil Biodiversity-Biofertilizers, ICAR-Indian Institute of Soil Science, Bhopal, India.
⁶ Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.
⁷ Department of Life Sciences, Yeungnam University, Gyeongsan, Republic of Korea.
⁸ Department of Environmental Science, V. B. S. Purvanchal University, Jaunpur, India.

Abstract

Copper oxide nanoparticles (CuO-NPs) have piqued the interest of agricultural researchers due to their potential application as fungicides, insecticides, and fertilizers. The Serratia sp. ZTB29 strain, which has the NCBI accession number MK773873, was a novel isolate used in this investigation that produced CuO-NPs. This strain can survive concentrations of copper as high as 22.5 mM and can also remove copper by synthesizing pure CuO-NPs. UV-VIS spectroscopy, DLS, Zeta potential, FTIR, TEM, and XRD techniques were used to investigate the pure form of CuO-NPs. The synthesized CuO-NPs were crystalline in nature (average size of 22 nm) with a monoclinic phase according to the XRD pattern. CuO-NPs were found to be polydisperse, spherical, and agglomeration-free. According to TEM and DLS inspection, they ranged in size from 20 to 40 nm, with a typical particle size of 28 nm. CuO-NPs were extremely stable, as demonstrated by their zeta potential of -15.4 mV. The ester (C=O), carboxyl (C=O), amine (NH), thiol (S-H), hydroxyl (OH), alkyne (C-H), and aromatic amine (C-N) groups from bacterial secretion were primarily responsible for reduction and stabilization of CuO-NPs revealed in an FTIR analysis. CuO-NPs at concentrations of 50 μg mL^-1 and 200 μg mL^-1 displayed antibacterial and antifungal activity against the plant pathogenic bacteria Xanthomonas sp. and pathogenic fungus Alternaria sp., respectively. The results of this investigation support the claims that CuO-NPs can be used as an efficient antimicrobial agent and nano-fertilizer, since, compared to the control and higher concentrations of CuO-NPs (100 mg L^-1) considerably improved the growth characteristics of maize plants.

Keywords: 16s-rDNA sequencing; CuO-NPs-green synthesis; antimicrobial and plant growth-promoting activity; confirmatory tests; novel bacterial isolate.

Grants and funding

Gratefully acknowledge the support by Researchers Supporting Project Number (RSP2023R410), King Saud University, Riyadh, Saudi Arabia. The financial assistance from All India Network Project on soil biodiversity and Bio-fertilizer project and MPUAT, India.