10.22376/ijpbs.2019.10.1.p1-12 Volume 7 Issue 1 2016 (January - March) The aim of present study was the evaluation of antibacterial activity of lessThan i greaterThan G. xanthochymus lessThan /i greaterThan seed extracts against some pathogenic bacteria like lessThan i greaterThan Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa lessThan /i greaterThan and lessThan i greaterThan Escherichia coli lessThan /i greaterThan and to analyze the mechanism of its antibacterial action by Atomic force microscopy (AFM). The minimum inhibitory concentrations varied from 12.5 to 50.0 µg/ml. The AFM study reveals that lessThan i greaterThan S. aureus lessThan /i greaterThan strain treated with petroleum ether extract showed a reduction in the cell size, formation of maximum cell clusters indicating the maximum damage to the cells whereas cell rupture and surface roughness was observed in lessThan i greaterThan B. cereus lessThan /i greaterThan and lessThan i greaterThan E. coli lessThan /i greaterThan strains treated with petroleum ether extract. The petroleum ether seed extract was responsible for the highest antibacterial activity against these strains. None of the seed extracts showed any activity against lessThan i greaterThan P. aeruginosa. lessThan /i greaterThan SHIVANAND PAYAMALLE AND HOSAKATTE NIRANJANA MURTH Garcinia xanthochymus; Antibacterial activity; Atomic force microscopy; Minimum inhibitory concentration 343-348