Design of a biodegradable carrier for the application of controller bacteria on air–water interfaces

MORELLI, MATÍAS N; SANTIAGO, LILIANA G; LEONARDI, RODRIGO J; HEINRICH, JOSUÉ M; IBAÑEZ, MANUEL; IRAZOQUI, HORACIO

PEST MANAGEMENT SCIENCE

JOHN WILEY & SONS LTD

Año: 2019

1526-498X

BACKGROUND: The formulation of a biodegradable carrier which effectively concentrates microorganisms on air-waterinterfaces is proposed. This avoids the dispersion of bacteria into the bulk liquid phase and at the same time prevents theirsedimentation. This formulation can be used in biocontrol and bioremediation treatments where the target is at the position ofthe air-water interface, as in the case of the treatment of rice diseases caused by Sclerotium oryzae and Rhizoctonia complex.The carrier is an oil-in-water (O/W) emulsion which contains lecithin and chitosan in both phases at different proportions. In astable formulation, bacteria that are adsorbed onto the surface of oil droplets are carried with them and flowed upward to theair-water interface, due to buoyancy forces.RESULTS: When using the biodegradable carrier, it is possible to recover at least 15-fold more bacteria from the air-waterinterface than in the case of using the aqueous formulation.CONCLUSION: The emulsion O/W is applied to the surface by dripping, resulting in homogeneous two-dimensional filmdistribution. With this application device, the number of bacteria at the air-water interface is significantly increased.© 2019 Society of Chemical Industry