Figure 1.

Purification of biofilm inhibitory polypeptide from Gs leaf extract fraction and growth of Sa in the presence of polypeptide. (A) The active principle of Gs leaf extract (water-ethanol, 1:1) was subjected to preparative IEF as described. Aliquots of samples from IEF fractions (3-20) were separated on SDS-PAGE (4-20%) under reduced conditions and Coomassie blue stained. Migration of the stained polypeptide (~4.2 kDa) is shown (arrow, #14-18) below to the 6 kDa protein standard. Original active fraction (Gs) was included during SDS-PAGE, and a weakly stained diffuse polypeptide band can be seen (asterisk). (B) Growth of Sa without or with purified polypeptide (15 µg/ml) in TSB at 37°C. The purified polypeptide increased slightly the growth rate of Sa at late exponential phase under the conditions tested.