AimsTo establish the ability of the rhamnolipids biosurfactants from Pseudomonas aeruginosa, in the presence and absence of caprylic acid and ascorbic acid, to disrupt bacterial biofilms, compared with the anionic alkyl sulphate surfactant Sodium dodecyl sulphate (SDS). Methods and ResultsPseudomonas aeruginosa ATCC 15442 biofilms were disrupted by rhamnolipids at concentrations between 05 and 04gl(-1) and with SDS at 08gl(-1). The combination of rhamnolipids 04gl(-1) and caprylic acid at 01gl(-1) showed a remarkable effect on biofilm disruption and cell killing. After 30min of treatment most of the biofilm was disrupted and cell viability was significantly reduced. Neither caprylic acid nor ascorbic acid has any effect on biofilm disruption at 01gl(-1). SDS is an effective antimicrobial agent; however, in the presence of caprylic acid its effect was neutralized. ConclusionsThe results show that rhamnolipids at low concentration in the presence of caprylic acid are promising molecules for inhibition/disruption of biofilms formed by Ps.aeruginosa ATCC 15442. Significance and Impact of the StudyThe disruption of biofilms has major significance in many industrial and domestic cleaning applications and in medical situations.