Antimicrobial activities of spice ethanol extracts
The growth inhibition zones measured by using agar
disc diffusion assay are presented in Table 1. In general,
S. aureus (Gram-positive bacteria) is more sensitive to
extracts than E. coli (Gram-negative bacteria). These
results are in substantial agreement with many previous
studies (Burt, 2004; Maillard, 2002). Turmeric showed
less inhibition in growth of both S. aureus and E. coli.
Galangal extract exhibited the strongest inhibitory
activity against S. aureus. Extract of galangal, krachai
and ginger had no effect against E. coli. All of these
results demonstrate that extract of galangal should be
used for further studies about antimicrobial activity
against other microorganisms, MIC and MBC of
galangal extract against S. aureus and electron microscopy..