Hata, E. M. | bioRxiv Science

bioRxiv2025

Nano formulation development and antibacterial activity of cinnamon bark extract-chitosan composites against burkholderia glumae, the causative agent of bacterialpanicle blight in rice

Bacterial panicle blight (BPB) disease, caused by Burkholderia glumae, poses a significant threat to rice production. Conventional chemical control methods contribute to environmental concerns and resistance issues, necessitating the development of sustainable alternatives. This study aimed to formulate and evaluate cinnamon bark extract-chitosan (CBE-CS) nano formulations for antibacterial efficacy against Burkholderia glumae. First, the antibacterial activity of cinnamon bark extract (CBE) was assessed, revealing a minimum inhibitory concentration (MIC) of 6.25 g/mL and a minimum bactericidal concentration (MBC) of 12.5 g/mL. Morphological analysis using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and transmission electron microscopy (TEM) showed significant bacterial cell wall damage, cytoplasmic leakage, and structural degradation after treatment. Chemical characterization of CBE using gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR) identified key active compounds, with (Z)-3-phenylacryldehyde as the major component (51.24%). Next, nano formulations of CBE-CS were developed, and their physicochemical properties were characterized, including particle size, zeta potential, encapsulation efficiency (33.9%), and loading capacity (48.78%). Antibacterial assessments demonstrated that the nano formulations effectively inhibited Burkholderia. glumae. Finally, greenhouse trials on rice seedlings confirmed the efficacy of these nano formulations in controlling BPB disease, showing significant bacterial suppression and improved plant health. These findings suggest that CBE-CS nanoparticles offer a promising, eco-friendly alternative for managing bacterial blight in rice, providing both effective antibacterial activity and enhanced plant protection.

pathology↗

bioRxiv2024

Nanobactericides Derived from Cinnamon Bark Extract: Phytochemical Profiling and Antibacterial Efficacy Against Bacterial Panicle Blight in Rice

Bacterial panicle blight (BPB), caused by the Gram-negative aerobic bacterium Burkholderia glumae (B.glumae), poses a significant threat to global rice production. Cinnamon bark extract (CBE) has demonstrated potent antioxidant and antimicrobial properties due to its high concentration of bioactive compounds, including eugenol and cinnamaldehyde. To enhance the efficacy and stability of these volatile compounds, this study employed nanotechnology and encapsulation techniques. The objective was to develop a CBE-based nanoformulation to inhibit B. glumae and control BPB in rice. CBE-chitosan (CBE-CS) nanoformulations were synthesized using ionic cross-linking between chitosan and trisodium phosphate (TPP) at various concentrations (0%, 0.5%, 1%, 2%, and 4% TPP). More than 15 active compounds were identified in CBE, including (Z)-3-Phenylacrylaldehyde, 2-Propenoic acid, 3-(2-hydroxyphenyl), cinnamaldehyde dimethyl acetal, and hexadecanoic acid. Bacterial membrane damage was significantly greater in treatments with CBE compared to untreated controls. The synthesized nanoparticles ranged in size from 43.66 nm to 106.1 nm, with encapsulation efficiencies between 48.65% and 48.78%, and loading capacities between 25.65% and 33.9%. Scanning electron microscopy (SEM) revealed spherical and homogeneous nanoparticles, while FTIR and XRD analysis confirmed the successful encapsulation of CBE in the chitosan nanoparticles. The antibacterial activity of the nanoformulations showed inhibition zones ranging from 7.5 to 11.8 mm, with the CBE-CS formulation containing 0.5% TPP demonstrating the highest efficacy (MIC = 15.6 mol/ml; MBC = 31.25 mol/ml).

plant biology↗