Disruption of Streptococcus mutans Biofilm by Rhamnolipid Biosurfactant Secreted from Pseudomonas aeruginosa ATCC10145

摘要

Objectives: The study was to examine the effect of rhamnolipid biosurfactant on Streptococcus mutans biofilm formation on orthodontic appliances. Methods/Statistical Analysis: Several properties of S. mutans cells such as formation of biofilm, detachment ability, the surface properties were changed after three different concentrations of biosurfactant treatment which were 10 mg/ml, 5 mg/ml and 2.5 mg/ml. S. mutans biofilms were disrupted by rhamnolipids produced by Pseudomonas aeruginosa ATCC10145 at different concentrations and chlorhexidine digluconate 0.12% (v/v) was used as positive control. Findings: The biosurfactant showed some antimicrobial activities against S. mutans with Minimum Inhibitory Concentration (MIC) varied from 10 mg/ml to 0.01 mg/ml. MIC were observed at 1.25 mg/ml by microdilution 96-well plate method. The Minimum Bactericidal Concentration (MBC) was detected at a higher concentration of 10 mg/ml by plating onto agar. The best treatment of dental biofilm formation was determined at 10 mg/ml showing the highest percentage of biofilm detachment which was 89.53%. The biofilm development is commonly known as strongly dependent on hydrophobicity/hydrophilicity substrate properties using contact angle measurement. Higher percentage (89.53%) of biofilm detachment determined at polystyrene surface compared to stainless steel surface with the aid of rhamnolipid. Rhamnolipid displayed a significant potential as disrupting agents against established biofilms produced by several bacterial and fungal species. Application/Improvements: P. aeruginosa were successfully extracted their crude biosurfactant to treat the growth of biofilm. Future studies can be performed on specific mechanisms on how biosurfactant inhibit and disrupt biofilm growth.