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

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.

Bioinspired Green Synthesis of Zinc Oxide Nanoparticles from a Native Bacillus cereus Strain RNT6: Characterization and Antibacterial Activity against Rice Panicle Blight Pathogens Burkholderia glumae and B. gladioli

“…Furthermore, the EDS analysis revealed the presence of Zinc (57.05%), oxygen (30.30%), phosphorus (10.90%) silicon (0.39%), sulfur (0.83%), and aluminum (0.52%) in biogenic ZnONPs (Figure 4c). Our EDS results corroborate with the study of Ogunyemi et al [22], who observed the elemental percentage, e.g., zinc (80.35%) and oxygen (19.65%) of ZnONPs. 3b).…”

“…Our results are constant with previous study of Jayaseelan et al [46], who observed the growth inhibition of the bacterial pathogen Pseudomonas aeruginosa in solid and liquid medium by ZnONPs. Similarly, Ogunyemi et al [22] reported the in vitro antibacterial activity (zone of inhibition and MIC at OD600) of ZnONPs against rice bacterial pathogen, while a comparatively greater inhibition effect of biogenic ZnONPs against B. glumae and B. gladioli was observed in our study as compared with the study of Ogunyemi et al [22]. In another recent study, Yusof et al [42] synthesized ZnONPs by using the supernatant of Lactobacillus plantaruma and observed their antibacterial activity against bacterial pathogens at 1000 µg mL −1 , a high dose of ZnONPs, as compared with our study.…”

“…ROS production in rice pathogenic bacteria B. glumae and B. gladioli was assessed by using dichlorofluorescein-diacetate (DCFH-DA) (Sigma-Aldrich, Saint Louis, MO, USA) as previously described by the method of Ogunyemi et al [ 22 ]. In brief, 1 mL overnight culture of bacteria (10 8 CFU mL −1 ) was centrifuged at 8000× g for 5 min.…”

“…In the previous literature, the use of zinc oxide nanoparticles (ZnONPs) as an antibacterial agent is a well-known effective approach and has received considerable attention in plant disease management due to their unique physico-chemical properties [18][19][20][21]. Moreover, numerous studies have reported that ZnONPs significantly increase plant growth and inhibit the growth of broad-spectrum pathogens [22,23]. An earlier study reported that green ZnONPs significantly inhibited the growth of rice pathogens Xanthomonas oryzae pv.…”

“…Another study performed by Zhou et al [ 28 ] showed the adverse impact of chemically produced ZnONPs on soil microorganism biomass and rac-metalaxyl transformation. However, microbe-based synthesis of ZnONPs has enormous potential benefits in terms of long-term stability, nontoxicity, eco-friendliness, and ease of scaling-up as compared to those NPs fabricated via chemical and physical methods [ 22 ]. Nevertheless, the ameliorative effect of green ZnONPs against B. glumae and B. gladioli is not being investigated.…”