Antibacterial Activity of the Himalayan Lichen Parmotrema nilgherrense Extracts

The antibacterial activity of the methanol, ethanol, chloroform and aqueous extracts of the lichen Parmotrema nilgherrense collected from Nainital, Kumaun Himalaya, has been investigated. The extracts were tested against five pathogenic bacteria (Bacillus subtilis, Erwinia chrysanthemi, Escherichia coli, Agrobacterium tumefaciens and Xanthomonas phaseoli) using agar-well method. All the extracts of P. nilgherrense were found effective by showing a mark zone of inhibition (ZOI) except aqueous extract. The chloroform extract exhibited potential antibacterial activity against the tested microorganisms (ZOI, 23-38mm) followed by ethanol and methanol extract (ZOI, 12-24 mm). Solvents treated wells were used as negative control and wells filled with standard antibiotic served as positive control in the experiment. Obtained results showed that P. nilgherrense extracts possess a broad-spectrum activity against a panel of bacteria responsible for the most common plants and animal diseases.