Fermentors hollow fibers

Batch cultivation is perhaps the simplest way to operate a fermentor or bioreactor. It is easy to scale up, easy to operate, quick to turn around, and reliable for scale-up. Batch sizes of 15,000 L have been reported for animal cell cultivation [2], and vessels of over 100,000 L for fermentation are also available. Continuous processes can be classified into cell retention and non-cell retention. The devices typically used for cell retention are spin filters, hollow fibers, and decanters. Large-scale operation of continuous processes can reach up to 2,000 L of bioreactor volume. Typically, the process is operated at 1-2 bioreactor volumes... 

S. Naser, R. Fournier, A numerical evaluation of a hollow fiber extractive fermentor process for the production of ethanol, Biotechnology Bioengineering, 32(5), 628-638, 1988... 

Chen and Lee [24] studied lactic acid production from dilute acid pretreated a-cellulose and switchgrass by L. delbruckii NRRL-B445 in the presence of a fungal cellulase in a fermentor extractor employing a microporous hollow fiber membrane (MHF). This reactor system was operated in a fed-batch mode with continuous removal of lactic acid by in situ extraction. A tertiary amine (alamine... 

Bosetti et al [4.29] have reported the oxidation of naphthalene by Pseudomonas fliioroscens to optically pure cA-1,2-dihydroxy-1,2-dihydronaphtalene. They reported that the MBR, after 25 h of reaction, had a production rate three times that of a batch reactor. Recently Miyano et al [4.30] reported improvement in the rate of vitamin B12 production by Propionibacterium freudenreichi using a hollow-fiber MBR. The strain used produced also propionic and acetic acid, which inhibit its activity. The authors compared the MBR with a batch reactor using a co-culture. For the batch reactor application, a second strain Ralstodia. Eutropha), which was able to metabolize partially the toxic propionic acid, was introduced into the fermentor. The experimental results of Miyano et al [4.30] showed that the MBR was much more efficient than the co-culture batch operation. 

Bioreactors utilizing UF hollow fibers appear to have tremendous potential for continuous enzyme reactors and fermentors. 

Continuous fermentation processes can also be carried out in a hollow fiber fermentor (HFF).85 Cells are packed into the shell side of a hollow fiber module, while substrate solution is fed to the core of the fibers (Figure 7.41). Since the cell slurry is separated from the substrate solution by the membrane, HFFscan be used for fermentation of liquid streams containing low molecular weight fermentable substances. A careful choice of membrane molecular weight cut-off can also assure that the cell environment is fully sterilized. Figure 7.45 shows typical performance of an HFF for whey permeate fermentation to ethanol by... 

Figure 7.45 Fermentation kinetics of a hollow fiber fermentor in single pass mode processing whey permeate (45 g/fi lactose concentration). Initial cell concentration = 117 g/fi. ( ) lactose, (A) ethanol, ( ) productivity.85...

Shukla R, Kang W, Sirkar KK. 1989. Acetone-butanol-ethanol (ABE) production in a novel hollow fiber fermentor-extractor. Biotechnol. Bioeng. 34 1158-1166. 

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