Production of microbial alginate in a membrane bioreactor

摘要: The extraction of bacterial alginate from fermentation broths Azotobacter vinelandii NCIMB 9068 was performed using crossflow filtration through ceramic membranes varying nominal pore sizes (0.2–1.4 μm). 1.4 μm membrane did not retain bacteria and found inadequate for this application. For the other membranes, permeation percentage (viscometric) average molecular weight filtered increased with size. Membrane fouling observed all but decreased Therefore, 0.8 selected continuous production in a bioreactor. Alginate efficient about 70 h, subsequently occurred. A total 7.55 g polysaccharide recovered permeate, rate (0.09 h−1), yield (0.21 g−1 sucrose), volumetric productivity (0.014 dm−3 h−1) specific (0.022 cell being significantly higher than batch process. varied over period to stabilize at very low value (6 kDa) later phase incubation.