Fig. 8

Antibacterial activities of rice seed crude extracts from wild Oryza species measured by MTS assay. Antibacterial activities of husk (a–c) and brown rice (d–f) crude extracts were measured. Two cultivated rice, Kasalath (KS) and Nipponbare (NB), were added as a control. Solvents for extraction were 80% MeOH (a, d) acetone (b, e), and sterilized water (c, f), respectively. x axis indicates the name of the extracts. y axis indicates relative growth rate of E. coli, which represents the antibacterial activity of the sample extracts. DMSO and antibiotics (ampicillin and kanamycin) are negative and positive controls of antibacterial activity. Stock solution of extracts were diluted by the concentration of extracts using either 2.5 seeds (a, c) or 5 seeds (b) for extraction and used for the measurement. All measurements were triplicated. Values indicate means. Error bars indicate standard deviation. N.D. indicates undetectable level of antibacterial activity. IC50 indicates 50% of maximum inhibitory concentration of ampicillin, which is a positive control