INDIAN SCIENCE CONGRESS - India Environment Portal

Section XIV : Plant Sciences 63
79. Antibacterial Evaluation of Leaf Extracts of Araucaria Cunninghamii
Sweet. from Kumaun Himalaya
Savita Joshi and S. C. Sati
Department of Botany,
D. S. B. Campus,
Kumaun University,
Nainital-236002
Keywords : Antibacterial activity, Araucaria cunninghamii, Crude extract,
Kumaun
Kumaun Himalaya possesses a great wealth of medicinal plants. In recent
times due to rapid development of multidrug resistant bacterial strains and
high cost of new generation antibiotics forced the interest of scientist to look
for the antimicrobial substances from natural sources. Therefore, the present
study was undertaken to explore the antibacterial activity of Araucaria
cunninghamii Sweet. (Araucariaceae), a gymnospermous plant of Kumaun
Himalaya and ethnobotanically well known for its medicinal properties.
Chloroform, ethanol and water extract of A. cunninghamii were tested against
five pathogenic strains (Bacillus subtilis, Agrobacterium tumefaciens, Escherichia
coli, Erwinia chrysanthemi and Xanthomonas phaseoli) employing
Disc diffusion method.
Chloroform and ethanol extracts of A. cunninghamii were found effective by
showing a mark zone of inhibition except aqueous extract. The ethanol extract
showed maximum inhibition against the test microorganisms (ZOI, 13-17mm)
followed by chloroform extract (ZOI, 10-14mm). The inhibitory activity of these
extract were found very promising as compared to ampicillin (10mcg) and
erythromycin (15mcg) standard antibiotics which were used as positive control
against these tested microorganisms. These results of different extracts of A.
cunninghamii indicate their broad spectrum activity against a panel of bacteria and
can be exploited for the management of the most common human and plant
bacterial diseases.