title: Enzyme recovery during gas/liquid two-phase flow microfiltration of enzyme/yeast mixtures.
abstract: The effect of a gas/liquid two-phase flow on the recovery of an enzyme was evaluated and compared with standard crossflow operation when confronted with the microfiltration of a high-fouling yeast suspension. Ceramic tubular and flat sheet membranes were used. At constant feed concentration (permeate recycling) and transmembrane pressure, the results obtained with the tubular membrane were dependent on the two-phase flow pattern. In comparison with single-phase flow performances at the same liquid velocity, the enzyme transmission was maintained at a high level with a bubble flow pattern but it decreased by 70% with a slug flow, whatever the flow rate ratio. Identical results were obtained with flat sheet membranes: for the highest flow rate ratio, the enzyme transmission was reduced by 70% even though the permeate flux was improved by 240%. During diafiltration experiments with the tubular membrane, it was found that a bubble flow pattern led to a 13% higher enzyme recovery compared to single-phase flow conditions, whereas with a slug flow the enzyme recovery was strongly reduced. With bubble flow conditions, energy consumption was minimal, confirming that this flow pattern was the most suitable for enzyme recovery.
authors.affiliation: Centre de Bioingénierie Gilbert Durand, UMR INSA-CNRS 5504 UMR INSA-INRA 792, 135, Avenue de Rangueil, 31077 Toulouse cedex 4, France. mercierb@insa-tlse.fr
authors.forename: Muriel
authors.initials: M
authors.lastname: Mercier-Bonin
authors.forename: Christian
authors.initials: C
authors.lastname: Fonade
mesh_terms: D000327:Adsorption; D003102:Colloids / Q000737:chemistry / Q000302:isolation & purification; D004795:Enzyme Stability; D004798:Enzymes / Q000302:isolation & purification; D005740:Gases; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification*; D008567:Membranes, Artificial; D010539:Permeability; D011208:Powders; D011786:Quality Control; D015203:Reproducibility of Results; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012996:Solutions; D014462:Ultrafiltration / Q000295:instrumentation / Q000379:methods*; D043324:beta-Fructofuranosidase
chemical_list: D003102:Colloids; D004798:Enzymes; D005740:Gases; D008567:Membranes, Artificial; D011208:Powders; D012996:Solutions; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase