Study of antimicrobial activity and atomic force microscopy imaging of the action mechanism of cashew tree gum

► Pure gum presented higher activity against all studied bacteria with the exception of L. acidophilus. ► Crude gum presented activity only against Gram-positive bacteria and at higher CMI values than pure gum. ► Only crude gum presented bactericidal concentrations and only for Gram positive bacteria. ► Optical density measures showed that cashew gum maintained its inhibitory activity over time. ► AFM imaging showed that 10 mg/ml of pure cashew gum acted upon the cell wall leading to the collapse of the cellular structure.