Identification of three inducible and extracellular enzymatic activities working on sucrose in Bacillus subtilis NCIMB 11871 and 11872 supernatant

Three inducible and extracellular activities produced by Bacillus subtilis NCIMB 11871 and 11872 were identified: a fructosyl transferase, a sucrase and a polymerase activity synthesising fructose polymers. These polymers are responsible for a limitation in the oxygen transfer, probably by increasing the viscosity of the culture medium, and for an opalescent supernatant observed at the end of the exponential growth phase. The production and degradation of the three enzymatic activities was tightly coupled during the time course of micro-organism cultivation. Furthermore, no separation of them was achieved by ammonium sulphate precipitation, ultrafiltration and other separation techniques. We suggest that these three activities are supported by the same enzyme, and that this enzyme is a levansucrase.