Related Experiment Video
Updated: Jan 30, 2026

Field-Deployable Candidatus Liberibacter asiaticus Detection Using Recombinase Polymerase Amplification Combined with CRISPR-Cas12a
Published on: December 23, 2022
Characterization and Antibacterial Activity of Oil-In-Water Nano-Emulsion Formulation Against Candidatus Liberibacter
C Y Yang1, C A Powell2, Y P Duan3
1State Key Lab for Conversation and Utilization Subtropical Aro-Biological Resources, Guangxi University, Nanning, Guangxi, 530005, China, IRREC-IFAS, University of Florida, Fort Pierce, FL 34945, and Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Abstract:
Nano-emulsion is a promising delivery system for increasing pesticide use and enhancing the therapeutic efficiency against pathogens. The pathogen Candidatus Liberibacter asiaticus (Las) that causes destructive citrus huanglongbing (HLB) resides in citrus phloem, which makes it difficult to treat with chemicals. Based on various physiochemical characteristics of oils, surfactants, and organic solvents, an oil-in-water (O/W) nano-emulsion formulation was developed and optimized to combat citrus HLB. The nano-emulsion was formulated through a spontaneous emulsification method for efficient delivery of ampicillin into the citrus phloem using bark application. The nano-emulsion that was prepared from Cremophor EL (viscous oil), acetone (water miscibility organic solvent), and Span 80/Tween 80 (surfactant) formed a small droplet size (17.33 ± 0.52 nm) and exhibited an improved absorption rate. Peak concentration was detected at 2 days posttreatment and the maximum concentration (Cmax) and relative bioavailability (RBA) of ampicillin in HLB-affected citrus were 71.86 ± 35.38 ng/g and 267.25% ± 44.1%, respectively. The peak concentration of Amp appeared at 6 days posttreatment in the citrus trees that were treated with Amp alone and their Cmax and RBA were 56.44 ± 32.59 ng/g and 100%, respectively. The same nano-emulsion was used to deliver five different antimicrobials to control citrus HLB through bark application. We found that the droplet size of the antimicrobials in the nano-emulsion was significantly reduced and the nano-emulsion also enhanced the therapeutic efficiency of validoxylamine A alone and in combination with actidione as well as sulfadimoethoxine sodium against Las. Therefore, this study provides an efficient bark application nano-emulsion formulation for citrus HLB control.
More Related Videos
Related Concept Videos
States of Water
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water and Mineral Acquisition
The Water Cycle
Cartesian Form for Vector Formulation
Resultant Moment: Vector Formulation
The resultant moment of a system of forces can be calculated through vector formulation. For example, if we consider...
Couples: Scalar and Vector Formulation
A couple moment is a rotational force that tends to rotate the steering wheel. The wheel's rotation can either be in a clockwise or anticlockwise direction. The right-hand rule is a helpful method for determining the direction of a couple moment....

