Abstract

The species of Parmelia mentioned in India Materia Medica are useful in treating a number of ailments and they are used in large quantities as food supplement in India. In this study, the crude extracts obtained from the Parmelia perlata by cold and hot extraction method using different solvents were tested for their antimicrobial activity. Results indicated that the antibacterial activity of P. perlata crude extracts was more on Clavibacter michiganensis, moderate on Pseudomonas solanacearum and it was less on Escherichia coli than streptomycin. The Fusarium oxysporum and Rhizopus nigricans were more susceptible, andAspergillus niger was less susceptible to all crude extracts than bavistin. The antibacterial activity was also high in compound-I and compound-II and it was least in compound-III, than streptomycin. The antibacterial activity of compound-II acted highly against C. michiganensisand P. solanacearum; it was less against to E. coli. The compound-I and compound-III were more active against C. michiganensis, moderately active against P. solanacearum and less active against to E. coli when compared to streptomycin. The antifungal activity was more in compound-II and moderate in compound-I and it was less in compound-III .The compound-II was more active against F. oxysporum and R. nigricans than compound-I and compound-III, and less active against A. niger than bavistin. The compound-I and compound-III did not show any activity against A. niger. The overall data presented indicates that the crude and isolated compounds of P. perlata extracts have antimicrobial property, in that antibacterial activity was found in all extracts than antifungal activity.

Key words: Antimicrobial activity, extraction, agar diffusion.