LAUSR

Bacteria are becoming resistant to new generation antibiotics day by day, which in turn lead us to find new antibacterial compounds of plant origin. Objective of this study was to assess in-vitro antibacterial activities of methanol extractives of fruits of four plants namely Kleinhovia hospita, Callistemon citrinus, Barringtonia acutangula and Polyalthia suberosa against four human and eight fish pathogenic bacteria by measuring the zone of inhibition (in mm), Minimum Inhibitory Concentration and Minimum Bactericidal Concentration. Characterization and isolation of active compounds through phytochemical screening, FT-IR analysis, Thin Layer Chromatography (TLC) and GC-MS analysis were done in most effective extract i.e., in C. citrinus fruit methanol extract among four tested plant extracts. All the tested bacteria (human and fish pathogens) were found to be susceptible to all four plant extracts used. Highest zone of inhibition (20.17±0.24mm) was found in C. citrinus fruit extract against Gram-positive bacterium, Staphylococcus aureus (MTCC 2940) indicating more sensitivity of Gram-positive bacteria than the Gram-negative bacteria examined. Presence of several bioactive compounds as detected through FT-IR, TLC and GC-MS analysis might be accountable for the significant efficacy of fruit methanolic extract of C. citrinus as antibacterial agent against both human and fish pathogenic bacteria.