International Journal of Current Microbiology and Applied Sciences

ISSN: 2319-7706 Volume 2 Number 10 (2013) pp. 26-30

Evaluation of antibacterial activity in three species of Costus

G.Sulakshana*, A. Sabitha Rani and B.Saidulu

Department of Botany, Osmania University College for Women, Koti, Hyderabad-500095, India *Corresponding author

ABSTRACT

The rhizome extract of three Costus species (Costus speciosus, Costus pictus and Costus igneus) were studied for their antibacterial activity against gram positive bacteria Bacillus subtilis (ATCC 633), Staphylococcus aureus (ATCC 9144) and gram negative bacteria Escherichia coli (ATCC25922), Pseudomonas aeruginosa (ATCC25619). Different concentrations of extract ranging from 500-2000 µg were used. The rhizome extract of three species inhibited the growth of all the test fungi. The zone of inhibition increased with increase in concentration of the test solution. High inhibition zone was observed in C.pictus against S. areus(1.26 cm) followed by P.aeruginosa(1.21 cm) followed by E.coli(1.18cm). B.subtilis showed low inhibition zone (1.12 cm). In C.speciosus the zone of inhibiton ranged from 1.25cm for S.areus followed by P.aeruginosa(1.21cm), E.coli (1.15 cm) and B.subtilis (1.10 cm). Higher activity of C.igneus rhizome extract was found against S.areus (1.20 cm), followed by P.aeruginosa(1.18cm), E.coli (1.11 cm)and B.subtilis (1.0 cm).

Keywords

Antibacterial activity; Costus species; rhizome extract; inhibition zones.