Recovery of α-Agarase Enzyme from Fermentation Broths by Membrane Crossflow Filtration

Abstract

We describe the recovery of extracellular α-agarase enzyme from fermentation broths using a polypropylene hollow fiber filter with 0.5 μm pores normally used for plasma collection from donors. The permeate flux increased with inlet wall shear rate from 30 L/h·m2 at 1500 s−1 to 45 L/h·m2 at 3000 s−1. But the enzyme activity sieving coefficient (ratio of permeate to inlet activity) decreased with increasing shear rate and transmembrane pressure (TMP). Therefore, the enzyme flux transmitted was found to be maximum at a shear rate of 1500 s−1 and a TMP between 20 and 40 kPa. Since enzyme activity decay with time is less at low temperature, the recovered activity was found to be nearly independent of temperature between 5 and 37°C, the maximum occurring at 22°C. The superimposition of flow and pressure pulsations on the inlet and outlet lines of the filter with a modified roller pump produced permeate flux enhancements ranging from 44% at 1000 s−1 to 68% at 3000 s−1 for a TMP of 3 kPa.