The Bio-Synthesis of Three Metal Oxide Nanoparticles (ZnO, MnO2, and MgO) and Their Antibacterial Activity Against the Bacterial Leaf Blight Pathogen.

Solabomi Olaitan Ogunyemi,Solabomi Olaitan Ogunyemi,Chengqi Yan,Chengqi Yan,Jianping Chen,Jianping Chen,Md Arshad Ali,Muchen Zhang,Yasmine Abdallah,Yasmine Abdallah,Bin Li,Wen Qiu,Temoor Ahmed,Yong Yang

doi:10.3389/fmicb.2020.588326

Abstract

Xanthomonas oryzae pv. oryzae (Xoo) is the most infectious pathogen of rice, which causes bacterial leaf blight (BLB) disease. However, the accumulation of chemical or antibiotic resistance of Xoo necessitate the development of its alternative control. In this study, we biologically synthesize three metal oxide nanoparticles (ZnO, MnO2, and MgO) using rhizophytic bacteria Paenibacillus polymyxa strain Sx3 as reducing agent. The biosynthesis of nanoparticles was confirmed and characterized by using UV-vis spectroscopy, XRD, FTIR, EDS, SEM, and TEM analysis. The UV Vis reflectance of the nanoparticle had peaks at 385, 230, and 230 nm with an average crystallite particle size 62.8, 18.8, and 10.9 nm for ZnO, MnO2, and MgO, respectively. Biogenic ZnO, MnO2, and MgO nanoparticles showed substantial significant inhibition effects against Xoo strain GZ 0006 at a concentration of 16.0 μg/ml, for which the antagonized area was 17, 13, and 13 mm and the biofilm formation was decreased by 74.5, 74.4, and 80.2%, respectively. Moreover, the underlining mechanism of nanoparticles was inferred to be in relation to the reactive oxygen species based on their antibacterial efficiency and the deformity in the cell wall phenomenon. Overall, an attractive and eco-friendly biogenic ZnO, MnO2, and MgO nanoparticles were successfully produced. Altogether, the results suggest that the nanoparticles had an excellent antibacterial efficacy against BLB disease in rice plants, together with the increase in growth parameter and rice biomass. In conclusion, the synthesized nanoparticles could serve as an alternative safe measure in combatting the antibiotic-resistant of Xoo.

Highlights

Xanthomonas oryzae pv. oryzae (Xoo) is affiliated to the gamma subdivision of Gram-negative proteobacterial with a single polar flagellum (Yang et al, 2007; Lee et al, 2008)
P. polymyxa strain Sx3 culture filtrate was added to the prepared zinc oxide (ZnO), magnesium oxide (MgO), and MnO2 solutions and applied to magnetic stirring for 24 h, the treatment without culture filtrate was used as the control
A final product of pale white nanoparticle was present for ZnO and MgO after freeze-drying, and light black color was showed for MnO2 nanoparticle after the synthesis process (Figures 1F–H)

Summary

Introduction

Xanthomonas oryzae pv. oryzae (Xoo) is affiliated to the gamma subdivision of Gram-negative proteobacterial with a single polar flagellum (Yang et al, 2007; Lee et al, 2008). Oryzae (Xoo) is affiliated to the gamma subdivision of Gram-negative proteobacterial with a single polar flagellum (Yang et al, 2007; Lee et al, 2008). It is rod-shaped having light yellow, circular and smooth colonies when grown on nutrient agar media (Jonit et al, 2016). Several management strategies have been used to combat this plant pathogen, but each has been met with certain drawbacks. Nanoparticles (NPs) have been successfully applied in the agriculture, health and food sector, providing eco-friendly alternative strategies for managing BLB (Peters et al, 2014)

Methods

Results

Discussion

Conclusion