Production and separation of alpha-agarase from Altermonas agarlyticus strain GJ1B

This paper presents results on the production of alpha -agarase by a fermen tation process and its separation using membrane microfiltration (MF). Opti mization of fermentation conditions for alpha -agarase production using Alt ermonas agarlyticus grown on medium containing agar as a carbon source was done in batch, fed-batch and continuous fermentations. Continuous culture a t a dilution rate of 0.03 h(-1) appeared to be best suited for production o f alpha -agarase by this organism. Al 0.03 h(-1) dilution rate, enzyme acti vity was 0.9 U/ml. Clarification of broth was done using a hollow-fibre mic rofiltration membrane. The influence of hydrodynamic parameters on permeate flux and enzyme activity was studied. The best performance was obtained wi th prefiltered fermentation broth. A stable permeate flux of about 250-270 ml/min.m(2) and an enzyme retention rate between 0% and 25% was obtained at temperatures between 6 degreesC and 22 degreesC, transmembrane pressure of 100 mm Hg and fluid cross-now velocity of 4 x 10(-2) m/s. From the experim ents on concentration of fermentation broth, the best compromise between en zyme activity transmission and permeate flux was obtained at a concentratio n factor of 2. (C) 2001 Elsevier Science Ltd. All rights reserved.