2.3.5 Antibacterial activity against E.coli and S.aureus
Samples were performed in dynamic shake flask method according to ASTM E2149-10. Bacteria was transferred
from stock culture to slant culture medium and then transferred into 5 ml NB tube. The tube was incubated at 37oC
for 16-24 hrs and then pipette 1 ml into 50 ml NB flasks. The thin films were irradiated with ultraviolet light at room
temperature for 2 hrs and then 0.3 g thin films were added into flasks and incubated at 37 oC for 20-24 hrs. The 10-
fold serial dilutions was made by using phosphate-buffered saline 9 ml/tube and pipette 1 ml of each flask into
dilution tube and dilute continuously to 9 tube.Then 0.1 ml of bacteria suspension in dilution factor 106-108 was
taken into sterilized plates containing 10 ml NB by pipette and then plates were incubated at 37 oC for 20 hr. All
experiments were conducted in triplicate. The colony forming units (CFU) of bacteria were taken count, and the
antibacterial rate (R) was calculated via the following equation (2) and (3), respectively.