Filtration of a bacterial fermentation broth: harvest conditions effects on cake hydraulic resistance

Martine Meireles (1) , Elodie Lavoute (1) , Patrice Bacchin (1)

1 LGC - Laboratoire de Génie Chimique

The hydraulic resistance of cakes formed on ultrafiltration of Streptomyces pristinaespiralis broths has been investigated for different harvesting conditions. Streptomyces pristinaespiralis broth was harvested after the point of microorganism activity decline (0-h aged broth) and held for different durations after that, up to 16 hours (16 aged broths). Aging behavior occurring between end of microorganism activity and harvest was compared for different acidification procedures (pH) and the mechanisms by which cake hydraulic resistance is affected have been investigated. For broths harvested in conditions where the acidification is fixed at pH 2 or 3, hydraulic resistance associated with cake build up is directly determined by the cells interactions. Holding broths beyond 5 hours contribute to a release of a soluble component from the cell surface. Enhanced cell surface interactions then turn the cake structure into a more open one and reduce the specific hydraulic resistance. For broths harvest in conditions where the acidification is fixed at pH 4, hydraulic resistance associated with cake build up is both determined by cell interactions and cell morphology. The cause of the increase in specific hydraulic resistance with aging is due to the binding of a soluble component released by the micro-organisms which decreases the cell surface interactions

Mots clés: ultrafiltration; cake hydraulic resistance; biotechnology; harvest time; CROSS-FLOW FILTRATION; MICROFILTRATION; YEAST; PROTEIN

Domaines: Génie des procédés

Martine Meireles, Elodie Lavoute, Patrice Bacchin. Filtration of a bacterial fermentation broth: harvest conditions effects on cake hydraulic resistance. Bioprocess and Biosystems Engineering, 2003, 25 (5), pp.309-314. ⟨10.1007/s00449-002-0310-0⟩. ⟨hal-00323069⟩