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

The hydraulic resistance of cakes formed during the ultrafiltration of Streptomyces pristinaespiralis broths has been investigated for different harvesting conditions. S. pristinaespiralis broth was harvested after the point of microorganism activity declines (0-h aged broth) and afterwards held for different durations of up to 16 h (16 aged broths). Aging behavior occurring between the end of microorganism activity and harvest was compared for different acidification procedures (pH) and the mechanisms for which the hydraulic resistance of the cake is affected by aging have been investigated. For broths harvested under conditions where the acidification is fixed at pH 2 or 3, hydraulic resistance associated with cake build-up is directly determined by the interactions between the cells. Holding broths beyond 5 h contributes 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 harvested under 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 microorganisms, which decreases the cell surface interactions.

[1]  Hidetoshi Yoshida,et al.  Filtration characteristics and structure of cake in crossflow filtration of bacterial suspension , 1994 .

[2]  C. Causserand,et al.  Modification of clay cake permeability by adsorption of protein , 1997 .

[3]  K. Nakanishi,et al.  ON THE SPECIFIC RESISTANCE OF CAKES OF MICROORGANISMS , 1987 .

[4]  Robert H. Davis,et al.  YEAST CAKE LAYERS AS SECONDARY MEMBRANES IN DEAD-END MICROFILTRATION OF BOVINE SERUM ALBUMIN , 1994 .

[5]  Gun Trägårdh,et al.  The effect of protein fouling in microfiltration and ultrafiltration on permeate flux, protein retention and selectivity: A literature review , 1993 .

[6]  Robert H. Davis,et al.  Microfiltration of protein mixtures and the effects of yeast on membrane fouling , 1999 .

[7]  P. K. Walsh,et al.  Effect of Cell Morphology on Dead‐End Filtration of the Dimorphic Yeast Kluyveromycesmarxianus Var. marxianus NRRLy2415 , 1998, Biotechnology progress.

[8]  Robert H. Davis,et al.  Effects of Added Yeast on Protein Transmission and Flux in Cross‐Flow Membrane Microfiltration , 1999, Biotechnology progress.

[9]  Y. Okamoto.  Harvest time effects on membrane cake resistance of Escherichia coli broth , 2001 .

[10]  Robert H. Davis,et al.  The behavior of suspensions and macromolecular solutions in crossflow microfiltration , 1994 .

[11]  Pierre Aimar,et al.  Model for colloidal fouling of membranes , 1995 .

[12]  P. Bobeck,et al.  Henry Darcy and the Public Fountains of the City of Dijon , 2003 .

[13]  C. Glatz,et al.  Effects of pH and ionic strength on microfiltration of C. glutamicum , 1999 .

[14]  HenryDarcy,et al.  The public fountains of the City of Dijon , 2004 .

[15]  K. Nakanishi,et al.  Crossflow filtration of yeast broth cultivated in molasses , 1994, Biotechnology and bioengineering.