Background: In Europe,
Acacia and
Eucalyptus
, originate large amounts of biomass, due to their need by industries and other
biological control, that can be used to extract antimicrobial substances.
Materials and Methods: Foliar aqueous, ethanolic and methanolic extracts of
Acacia baileyana
(Cootamundra wattle),
Acacia dealbata
(silver wattle),
Acacia melanoxylon
(black wattle) and
Eucalyptus nicholii (narrow-leaved black peppermint) were assessed
for antimicrobial activity against
Escherichia coli
,
Bacillus cereus
,
Candida albicans
and
Candida parapsilosis
, using the disc
diffusion method.
Results: Ethanolic extracts from
A. baileyana and
A. dealbata showed significant (P< 0.05) antimicrobial activity. Concerning the
microbial species tested, differences were found in
A. baileyana (P< 0.01) and
E. nicholii (P< 0.0001) extracts. These two extracts
were effective mostly against
B. cereus, followed by
C. parapsilosis. According to the antimicrobial activity classification, eucalypt
and Cootamundra and silver wattles extracts (both water and ethanol) presented good efficacy against
B. cereus, a food poisoning
agent, and moderate efficacy against the remaining microorganisms.
E. coli, a Gram negative, exhibited low sensibility to all foliar
extracts.
Conclusion: A. baileyana, E. nicholii and
A. dealbata foliar biomass could be used to develop alternative substances in microbial
control.
