Abstract:
The present research was carried out at the Institute of Biotechnology and Genetic Engineering, The
University of Agriculture Peshawar, KPK Pakistan. In this study crude methanolic extracts from Thuja occidentalis were
tested for their antimicrobial activity against five different bacterial strains (Bacillus subtilis, Escherichia coli, Klebsiella
pneumonia, Xanthomonas sp. and Staphylococcus aureus) at two different concentrations (10 and 20 mg/ml) using disc
diffusion assay. The results showed that Klebsiella pneumoniae was most sensitive to crude extracted sample from
leaves at both low and high concentrations measuring 37 and 57% zone of inhibition respectively and Xanthomonas and
Staphylococcus aureus was found to be more resistant to the crude extracted samples from leaves at both concentrations.
Similarly, Klebsiella pneumoniae was most sensitive to crude extracted samples from seeds at high concentration
followed by E. coli at both concentrations. Staphylococcus aureus on the other hand was found to be more resistant to
the crude extracted samples at low and high concentrations. These results suggested that extracts prepared from the
leaves and seeds of Thuja occidentalis can be used as natural remedy for the treatment of various bacterial infections.
