Cross‐flow membrane microfiltration of a bacteriol fermentation broth

Nagata, Naohiko; Herouvis, Kay J.; Dziewulski, David M.; Belfort, Georges

doi:10.1002/bit.260340405

Cited by 118 publications

(46 citation statements)

References 24 publications

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“…This is comparable to the results of Nagata et al [34] for certain ceramic membranes. The intercept was calculated to be 94.96 · 10\2; this gives a value of 4.2 kPa as the pressure required to initiate permeate flow.…”

Section: Bacteria-free Filtration Experimentssupporting

confidence: 92%

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Pressure effects in cross-flow microfiltration of suspensions of whole bacterial cells

Caridis

Papathanasiou

1997

Bioprocess Engineering

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The effect of Trans-Membrane Pressure (TMP) on permeate flux during cross-flow microfiltration of bacterial cell suspensions in tubular ceramic membranes is studied experimentally. Continuous filtration experiments with suspensions of whole bacterial cells (Mycobacterium M156) show a dramatic permeate flux decline with increasing TMP. During the very early stages of the filtration process, a linear relationship between permeate flux and TMP is observed, suggesting an initial surface sorption of cells on the membrane surface. At longer times, the permeate flux vs. TMP data exhibit a critical pressure beyond which the permeate flux declines with increasing trans-membrane pressure. This is interpreted in terms of the formation of a compressible cake, whose permeability can be described through the Carman-Kozeny equation. IntroductionThe application of conventional methods (such as dead-end filtration, sedimentation, and centrifugation) for the separation of cells from liquid streams in pharmaceutical applications in a continuous production line poses many practical difficulties, mainly because of the highly hydrated and glutinous character and of the low density of biological cells. An alternative method involves the use of cross-flow membrane filtration [1] in which the filtrate passes through the membrane by virtue of a pressure differential (the TransMembrane-Pressure or TMP). In cross-flow microfiltration, the product to be filtered is passed over a tubular or flat porous surface. The flowrate of the product stream across the surface tends to maintain the direction of flow and controls the thickness of the deposited cell layer. The cell suspension to be filtered is usually pumped at a velocity in the rage 1-8 m/s parallel to the surface of the membrane and with a TMP between 0.1-0.5 MPa. The liquid permeates through the membrane and the feed emerges in a more concentrated form at the exit of the module. The partially concentrated retentate can be recycled into the reactor while the permeate is removed for further processing. Figure 1 is a schematic description of the principle behind the operation of a crossflow microfiltration membrane.While the cross-flow mode is a significant improvement over dead-end filtration, permeate flux still decreases with time, even when the feed concentration is kept constant. Typical product fluxes of 0.138 · 10\4 m3 sec\1 m\2 to 0.415 · 10\4 m3 sec\1 m\2 are observed; these do not compare very favorably to threshold flux values of between 0.2 · 10\4 m3 sec\1 m\2 and 1.11 · 10\4 m3 sec\1 m\2 which have been quoted as necessary for cross-flow microfiltration to compete with such established operations as centrifugation and precoat filtration [2,3]. Still, the advantage of continuous operation afforded by cross-flow filtration has resulted in a sustained interest for this technology. Applications of cross-flow filtration include water and sewage treatment [4], harvesting of plant and animal cells [5], food processing [6] and dewatering of mineral slurries [7]. Both submillimetre and ...

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Section: Bacteria-free Filtration Experimentssupporting

confidence: 92%

“…It is customary in the analysis of cross-flow microfiltration using resistance models to define a ''permeability coefficient -P.C.'' as the slope of such a graph [33,34], based on the equation:…”

Section: Bacteria-free Filtration Experimentsmentioning

confidence: 99%

Pressure effects in cross-flow microfiltration of suspensions of whole bacterial cells

Caridis

Papathanasiou

1997

Bioprocess Engineering

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“…Both remain essentially unaffected by cell concentration between 2 and 4.5 g L −1 , in contrast to results of Nagata et al (1989) who observed a flux decay in conventional crossflow filtration. Initial increase in permeate and mass fluxes may be due to increase in shear stress due to concentration.…”

Section: Effect Of Cell Concentrationcontrasting

confidence: 81%

“…However, bacterial suspensions are notorious for fouling membranes, either by clogging the pores with cellular debris (Kroner et al, 1984), or by adsorption of dissolved matter or by formation of a highly compressible layer on the membrane (Nagata et al, 1989). This fouling produces a rapid decline of permeate flux and polymer transmission (Haarstrick et al, 1991).…”

Section: Introductionmentioning

confidence: 98%

Microfiltration and ultrafiltration of polysaccharides produced by fermentation using a rotating disk dynamic filtration system

Brou

Jaffrin

Ding

et al. 2003

Biotech & Bioengineering

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The recovery of exopolysaccharides (EPS) produced by Sinorhizobium meliloti bacteria by dynamic microfiltration was investigated using a rotating disk device designed in our laboratory, equipped with a 0.2 microm nylon membrane. This system differs from commercially available systems by the presence of vanes on the disk which produce a very important increase in permeate flux while yielding excellent EPS transmission. For polymers produced under standard fermentation conditions (70 h at 30 degrees C), the mass flux rose to 650 g h(-1) m(-2) using a disk equipped with 2 mm vanes rotating at 2000 rpm against 380 g h(-1) m(-2) with a smooth disk at the same speed. The maximum flux observed was 1560 g h(-1) m(-2) with a 6-mm vanes disk rotating at 3000 rpm and a 36 degrees C broth. An interesting finding was that the permeate flux J(f) for various disks can be correlated by the same function of the mean shear stress at the membrane tau(wm) according to J(f) = 4.6 tau(wm) (0.717) for a 30 degrees C broth, showing that the effect of vanes is merely to increase the shear stress by raising the fluid core velocity between the membrane and the disk. With 6-mm vanes the core angular velocity was found to be 84% of disk velocity vs. 45% for a smooth disk. When the fermentation temperature was increased to 36 degrees C to produce a lower molecular weight polymer, the permeate flux rose by about 250%, much more than what could be expected from the reduction in permeate viscosity and followed the same power law with membrane shear stress as for 30 degrees C. The same device was equipped with a PES 50 kDa membrane to concentrate EPS by ultrafiltration. Permeate fluxes were of the order of 160 L h(-1) m(-2) at 2000 rpm and 30 degrees C with nearly complete EPS rejection. Finally, the net electrical power consumed by the disk was measured by subtracting the power consumed without fluid from the power during filtration at the same speed. This power increases with speed and with the presence of vanes, but since the gain provided by the vanes is very high, the specific energy per m(3) of permeate is minimal with the highest vanes tested (6 mm) and maximal for smooth disks.

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“…More seriously fouling large molecule might have been formed by the interaction. Nagata et al (1989) [16] already reported on a case of interaction among medium components that potassium ammonium phosphate precipitate was formed during the steam sterilization of peptone salts growth medium. The precipitate was considered as the major foulant in harvesting of B. polymyxa by membrane micro®ltration.…”

Section: Influence Of Concentrations Of Glucose and Yeast Extractmentioning

confidence: 99%

Factors affecting membrane fouling in filtration of Saccharomyces cerevisiae in an internal ceramic filter bioreactor

Zhang

Park

Chang

et al. 1998

Bioprocess Engineering

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Filtration of ethanol fermentation medium and broth by using symmetric and asymmetric ceramic membranes has been studied in an internal ®lter bioreactor. Factors studied included membrane structure and pore size, medium sterilization, and concentrations of glucose, yeast extract in the medium, yeast cell and protein in broth. The aim was to determine the main factors responsible for the decline in ®ltration performance during ethanol fermentation by Saccharomyces cerevisiae. Flux index (Fi) of a new concept has been developed to evaluate the degree of¯ux decline during the membrane fouling process. Fi was de®ned as the ratio of the membrane¯ux at certain ®ltration time (t t) to the initial (t A0)¯ux of pure water, not the initial (t +0)¯ux of the test¯uid. Flux with sterilized medium was approximately two-fold higher than that with unsterilized medium although the reason could not be explained clearly. Glucose, interaction between glucose and yeast extract, yeast cells, and proteins in fermentation broth were found to play an important part in membrane fouling. Fi of the symmetric membrane decreased to a less extent than that of the asymmetric membrane with increasing glucose concentration. But, the result with various yeast cell concentrations turned out to be contrary. Fouling was more serious for asymmetric membrane during the ®ltration of fermentation supernatant. This was thought to be due to different fouling mechanisms for the two types of membrane.

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Cross‐flow membrane microfiltration of a bacteriol fermentation broth

Cited by 118 publications

References 24 publications

Pressure effects in cross-flow microfiltration of suspensions of whole bacterial cells

Pressure effects in cross-flow microfiltration of suspensions of whole bacterial cells

Microfiltration and ultrafiltration of polysaccharides produced by fermentation using a rotating disk dynamic filtration system

Factors affecting membrane fouling in filtration of Saccharomyces cerevisiae in an internal ceramic filter bioreactor

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