4. Conclusions
The leaf oil and the oil from the rhizomes of halia bara differed
in chemical composition, the former comprising mainly sesquiterpenoids
and monoterpenoids in approximately equal amounts,
while the latter was dominated by monoterpenoids. Antimicrobial
assays of these oils have demonstrated that the Gram-positive bacteria
in this study were more sensitive to both the oils compared to
the Gram-negative bacteria. Toward the leaf oil, B. licheniformis and
S. aureus were the most sensitive strains, while E. coli was the most
resistant strain. B. licheniformis and P. stutzeri were the most sensitive
and resistant strains, respectively, toward the oil of the rhizomes.
The sensitivity of the B. licheniformis, B. spizizenii, S.
aureus and E. coli strains toward both oils would suggest that these
oils may be promising natural preservatives in the food industry.
However, it is commendable that further analysis should be carried
out on other food poisoning agents, such as Listeria sp., Salmonella
sp.