초록
Bacterial exopolysaccharides (EPSs) are promising sustainable alternatives to synthetic polymers. Here we describe the production and characterization of different EPSs produced by the recently isolated Paenibacillus sp. 2H2. A final EPS titer of 4.54gL<SUP>-1</SUP> was recovered after a 17-h fermentation, corresponding to a volumetric productivity of 0.27gL<SUP>-1</SUP>h<SUP>-1</SUP>. Remarkably, supplying the fermentation with specific carbon and nitrogen sources could be exploited for the production of different polymers. A pure heteropolysaccharide composed of glucose, mannose, galactose, and glucuronic acid (3.5:2:1:0.1) was obtained when using glucose/glycerol and peptone as substrates. A pure levan-type polymer or mixture of both polymers was observed with sucrose and NaNO<SUB>3</SUB> or peptone. To our knowledge, this is the first report that nutrients, particularly nitrogen sources, can be used to fine-tune EPS production in Paenibacillaceae. Rheological characterization of the heteropolysaccharide revealed impressive thickening properties, suggesting its potential application in commodity materials.