Influence of bioreactor design on the rate and amount of curdlan-type exopolysaccharide production byAlcaligenes faecalis

Summary The amount of polymer recovered during lab-scale batch production of curdlan-type polysaccharide byAlcaligenes faecalis (ATCC 31749) was increased by 46% through the manipulation of the vessel configuration. When standard turbine impellers were used to provide mixing and agitation the specific rate of production, Qp, decreased significantly after 40–50 hours elapsed fermentation time, EFT. The Qp remained at a high level throughout the entire time course of production (90 hours) when (i) a propeller was substituted for a flat-blade turbine impeller in a conventional baffled stirred tank reactor, or (ii) agitation and mixing were accomplished in a non-rotary vibro-fermenter.