The antibacterial activity of eri sericin was preliminarily investigated by the disc diffusion assay. The Gram-negative E. coli was more susceptible to the 90-min Na2CO3 degummed eri sericin with an effective dose initially at 30 ตg (Fig. 1A), while the effective dose for the 60-
min water degummed eri sericin was at 40 ตg (data not shown). The Gram-positive S. aureus was strikingly restricted to inhibition by the 60-min water degummed eri sericin (Fig. 1B). The species’ differential susceptibility to different eri sericin is attributed to involve evolutionary distinct cell wall and/or cell membrane characteristics.