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.

米黄单胞菌 pv.米曲霉 (Xoo) 是水稻最具传染性的病原体，可引起细菌性叶枯病 (BLB) 病。然而，Xoo 化学或抗生素抗性的积累使得有必要开发其替代控制方法。在本研究中，我们使用根际细菌多粘类芽孢杆菌菌株Sx3作为还原剂，生物合成了三种金属氧化物纳米颗粒（ZnO、MnO ₂和MgO）。通过紫外可见光谱、XRD、FTIR、EDS、SEM 和 TEM 分析证实和表征了纳米颗粒的生物合成。纳米颗粒的UV Vis反射率在385、230和230 nm处具有峰值，ZnO、MnO ₂和MgO的平均微晶粒径分别为62.8、18.8和10.9 nm。生物源ZnO、MnO ₂和MgO纳米粒子在16.0 μg/ml浓度下对Xoo菌株GZ 0006表现出显着的抑制作用，拮抗面积分别为17、13和13 mm，生物膜形成减少74.5，分别为 74.4% 和 80.2%。此外，根据纳米颗粒的抗菌效率和细胞壁变形现象，推测纳米颗粒的基本机制与活性氧有关。总体而言，成功生产了有吸引力且环保的生物源ZnO、MnO ₂和MgO纳米颗粒。总而言之，结果表明纳米颗粒对水稻 BLB 病具有优异的抗菌功效，同时增加了生长参数和水稻生物量。总之，合成的纳米颗粒可以作为对抗 Xoo 抗生素耐药性的替代安全措施。