Sequential fermentation for enhanced volumetric productivity of bioethanol from mixed sugars

Most native strains efficiently ferment individual preferential sugars but not the mixed to bioethanol. Therefore, a two-stage sequential fermentation was carried out in single bioreactor vessel convert sugars, mixture of synthetic glucose and xylose, into bioethanol using Z. mobilis P. stipitis at stage-1 (glucose fermentation) stage-2 (xylose fermentation), respectively. A total 160 g/L (100 60 xylose) found be optimum for sugar fermentation. In fermentation, stage-1, an ethanol titer 50.25 with yield 0.50 g/g achieved no residual glucose. stage-2, significant conversion xylose observed due presence live cells; however, removing cells productivity resumed, overall were 56.77 0.36 g/g, Further, it when removed along complete removal cells, improves. On 80% ethanol, titer, yield, volumetric 79.03 g/L, 1.09 g/L/h, respectively, same upon 79.93 1.82 These values identical separate batch