FIGURE 2.

EPS synthesis by a secreted GS enzyme. (A) Total proteins from the supernatant (the secreted proteins) of both culture (Glc and Suc) were extracted by precipitation with (NH₄)₂SO₄ as described in Section “Materials and Methods.” Equivalent amount of total protein was separated on 8% SDS-PAGE and subjected to silver staining. A differential expressed protein band of ∼180 kDa was indicated by an arrowhead. (B) In situ detection of glucansucrase activity. A parallel SDS-PAGE was incubated in 50 mM sodium acetate buffer containing 50 g/L sucrose buffered at pH5.6. An active band was detected by the appearance of opaque polymer.