Zymomonas mobilis levan production in the presence of antimetabolic angents

Abstract

Our studies have focused on the screening of Zymomonas mobilis bacterial strains capable to
produce levan under the action of three antimetabolic agents (sulfafurozol, sulfametaxazol, trimetoprim). The
experiments were carried out using spontaneous mutant strains derived from Z.mobilis NCIB 11163 and 11163/70,
obtained by supplemented media with methotrexate (600 μg/mL) and trimethoprim (1000 μg/mL). Exponential growth
profiles of bacterial cells and the production of levan were assessed in the absence and presence of antimetabolites of
different concentrations. The studies have shown that Z.mobilis 11163/70 strains manifest a progressive growth in the
presence of trimethoprim (50 μg/mL), an inhibition growth in the presence of sulfametoxazol (100 μg/mL). and also good
resistance in the presence of sulfafurazol (100 μg/mL). Sulphonamides can inhibit the production of levan (Z.mobilis
CP4PRRif, Z.mobilis NCIB 11163/70). On the other hand, a stimulation of levan production has been observed in the
presence of trimetoprim (50 μg/mL) (Z.mobilis CP4Rif and 10988).