B. Braun

There several DO probes available. Some well-known branded fermenters, like New Brunswick, Bioflo series and the B. Braun Biotstat B fermenters are equipped with a DO meter. This unit has a 2 litre fermentation vessel equipped with DO meter and pH probe, antifoam sensor and level controllers for harvesting culture. The concentration of DO in the media is a function of temperature. The higher operating temperature would decrease the level of DO. A micro-sparger is used to provide sufficient small air bubbles. The air bubbles are stabilized in the media and the liquid phase is saturated with air. The availability of oxygen is major parameter to be considered in effective microbial cell growth rate. 

It is very simple to perform batch fermentation in a small flask with a volume of say 200 ml. Now our target is to use a 2 litre B. Braun fermenter. All accessories are shown in Figure 10.5. The fermentation vessel only, as shown in Figure 10.6, with about 250 ml of media without any accessories but with some silicon tubing attached with a filter for ventilation is autoclaved at a 131 °C for 10 minutes at 15psig.9 After that, the system is handled with special care and all accessories attached. Media is separately sterilised and pumped into the vessel. Inoculum is transferred and the batch experiment is started right after the inoculation of seed culture. An initial sample is withdrawn for analysis. 

The experiment is accomplished with a 2 litre B. Braun fermenter biostat (Germany) equipped with DO and pH meters. Temperature and level controllers are very sensitive, with highly accurate response from the sensors installed in the vessel. Figure 10.7 shows a perfect continuous fermentation set up used in photosynthetic production. A small modification of... 

Fig. 10.6. Geomeh ical dimensions of B. Braun fermentation vessel.

Fig. 10.7. A complete laboratory set-up of biostat, B. Braun fermenter with external feed pumps and product reservoirs.

The batch experiment had neither incoming fresh media nor any product stream leaving the fermentation vessel. A complete experimental set up with a B. Braun Biostat, is shown in the above laboratory experimental set up. The continuous flow of media requires a feed tank and product reservoir. The batch process has many disadvantages such as substrate and product inhibition, whereas in the continuous process the fresh nutrients may remove any toxic by-product formed. 

Citric acid fermentation of cane-molasses is by submerged fermentation in a 21 biostat (B. Braun) stirred fermenter. A strain of Aspergillus niger is the most widely used for commercial production. A. niger is also highly recommended in the present study, which can obtained from the American Type Culture Collection, Rockville, Maryland, USA. Molasses... 

Citric acid fermentation of cane-molasses by submerged fermentation in 21 B. Braun stirred fermenter (working volume 21) is performed. A strain of A. niger ATCC 11414 is... 

Prepare spores, fungal conidia/small pellets in Petri dish or cotton-plugged flask, for 48 hours. Harvest the spore in separate flask with media for propagation. Once in the separated flask the concentration of spores has reached to about 3 million per litre. It is now ready to be transferred to a 21 B. Braun biostat fermenter. The minimum volume of harvested spores in the flask is 300 ml. Media must be prepared based on sufficient carbon source... 

Prepare seed culture and use it for inoculation of 21 airlift and 21 B. Braun biostat B using soluble starch or glucose. 

Streptase (Hoechst) Streptokinase (B/Braun) Varidase (Lederle)-comb. Kabikinase (Pharmacia Upjohn)... 

Giicker B, Brauns M, Pusch M (2006) Effects of wastewater treatment plant discharge on ecosystem structure and function of lowland streams. J N Am Benthol Soc 25 313-329... 

Brodesser B, Braun M (1989) Phosphorus Sulfur Silicon Relat Elem 44 217-221... 

Rothen-Rutishauser, B., Braun, A., Gunthert, M., and Wunderli-Allenspach, H., Formation of multilayers in the Caco-2 cell culture model a confocal laser scanning microscopy study, Pharm. Res., 17, 460, 2000. 

Braun Potter-S tissue homogenizer (B. Braun Biotech Co., Melsungen, Germany)... 

Chatterjee, D., Burkhardt, T., Bandl-Konrad, B., Braun, T., Tronconi, E., Nova,... 

Regelmann, W.E., Talbot, R., Cairns, L., Martin, D., Millet, L.C., Zabriskie, J.B., Braun, D., and Gray, E.D. (1989) Distribution of cells bearing rheumatic antigens in periphetal blood of patients with rheumatic fever/rheumatic heart disease. / Rheumatol 16 ... 

Number in parentheses refer to product brands (1) B. Braun, (2) Fresenius, (3) Baxter, (4) Halex Istar, (5) JP, (6) Merck, (7) EMS, (8) Elkins Sinn, (9)Ariston, (10) Geyer, (11) Hipolabor. RSD, relative standard deviation n.d., not detected (below LOD). 

Standard adult amino acid solution, B. Braun... 

Suppliers Abbott, Ariston, Aster, Baxter, Behring, B.Braun, Darrow, Fresenius, Fujisawa, Gayer, Halex Istar, Hypofarma, Santisa, Roche, Zenalb. 

McGregor, D.B., Braun, A., Cattanach, P, Edwards, I., McBride, D., Riach, C. Caspary, WJ. (1988) Responses of the L5178Y tH/tk- mouse lymphoma cell forward mutation assay III 72 coded chemicals. Environ, mol. Mutag., 12, 85-154... 

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