Document Type
Poster
Date of Original Version
3-27-2026
Abstract
Green synthetized nanoparticles have been the object of study for their use as fertilizers in the agricultural field. Among them, manganese oxide nanoparticles (MnONPs) have been used to increase the growth and biomass of rice seedlings, mung bean, moringa plants, among others. In this work, we explore the biosynthesis and purification of MnONPs for these environmental applications, seeing as the biosynthesis of MnONPs consumes less thermal energy compared to chemical synthesis methods. In this study, MnONPs were biosynthesized using a strain derived from the marine environment, Pseudomonas putida GB-1. The bacteria were incubated in a batch system in Leptothorix media, enriched with MnCl2 as the manganese source, for 24 hours at 30 °C and 144 rpm, until the late stationary phase. During the incubation Pseudomonas putida GB-1 transforms aqueous Mn(II) to Mn(III/IV) particles. After 24 hours, the media was centrifuged at 3000 rpm for 10 minutes. The supernatant was collected and filtered for investigation using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), while the MnONPs pellet was re-suspended and soaked in absolute ethanol for 10 minutes aiming the dissolution of organic remnants to obtain a high yield of reactive particles. The pellet was then left to air dry for 48h and then analyzed in the XRF (X-ray Fluorescence) to determine the elemental composition of the remaining solids. The results showed a significant decrease of Mn concentration in the supernatant media after incubation (from ~2300 ppb to below detection level), suggesting the transformation of MnCl2 into MnONPs by the bacteria. Moreover, the elemental analysis of the pellet showed a high percentage of Mn in the remaining solids and possible formation of manganese and oxygen bonds, suggesting once more the formation of MnONPs. The particles obtained will be further characterized using Fourier Transform Infrared Spectroscopy, Energy-Dispersive X-ray Spectroscopy, Transmission Electron Microscopy, X-ray Diffraction, Zeta Potential and Inductively Coupled Plasma Optical Emission Spectroscopy. Moreover, after characterized, the nanoparticles will later be used as fertilizers by foliar application to soybean plants.
Recommended Citation
Welter, Nicoly and Oyandel-Craver, Vinka, "Biosynthesis of Manganese Oxide Nanoparticle for Agricultural Fertilization Application" (2026). Poster Presentations. Paper 24.
https://digitalcommons.uri.edu/gradcon2026-posters/24