The production of rhamnolipid (glycolipid) biosurfactant was achieved under optimized conditions from newly isolated bacteria (Pseudomonas plecoglossicida BP03) from rice mill effluent. The isolated biosurfactant was structurally characterized using FTIR and NMR spectroscopic studies. The obtained biosurfactant (1·39 g l-1 ) showed a variety of applications including larvicidal and pupicidal activity against malarial vector (Anopheles sunadicus). It also exhibited antimicrobial activity against human pathogens, and possessed potent anti-biofilm activity against Staphylococcus aureus, Bacillus subtilis and Aeromonas hydrophila. The obtained biosurfactant showed a dose-dependent inhibition of exopolymeric substance (EPS) and growth curve in S. aureus. Furthermore, the cytotoxicity assays revealed that the biosurfactant exhibit a cytotoxic potency against the human fibroblastic sarcoma cells Ht-1080. An in silco analysis was also performed using Schrodinger maestro 9.3 against surface protein (SasG) of S. aureus, and the resultant analysis revealed an interactive docking score of -3·4 kcal mol-1 . The obtained result indicates that the synthesized economically viable biosurfactant ensures excellent applications towards various fields.
Keywords: antimicrobial activity; biofilm; cytotoxicity; larvicidal activity; rhamnolipid; schrodinger maestro 9.3.
© 2020 The Society for Applied Microbiology.