NEW BRUNSWICK SCIENTIFIC BioFlo 415, Руководство по эксплуатации

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129
New Brunswick Scientific User’s Guide
For fermentation, the glucose solution is usually sterilized in a separate flask. It is
then added aseptically to the other (heat labile) components that cannot be subjected to
autoclaving, such as Ampicillin and the trace metal solution. These are prepared in
advance by sterile filtration so that they are available as stock solutions.
The magnesium sulfate is sometimes sterilized separately.
Most materials are available from a variety of vendors. Note that Sigma and Difco are
often the best sources for the more unusual biological and chemical materials. The
exact formulations of the trace metals solution and the fermentation media for the
fermentors will depend on the precise fermentation you wish to conduct. Various
formulations can be found in the handbooks and literature.
23.2 Antifoam Formulation
Question: What kind of antifoam should be used, and in what concentration?
Answer:
Please visit our website at www.nbsc.com (click on the
FAQs
tab, then click
on
Fermentation and Cell Culture
) for recommendations on types of antifoam agents
to use. The initial concentration of antifoam is usually 0.1-0.5 ml/L. When the foam
probe is used, the pumping of antifoam is controlled by the unit.
The pump should be set to add the minimum amount of antifoaming agent required to
prevent foaming in your particular process. That amount varies depending on the
amount of protein in the media, the amount of protein secreted by the microorganism,
agitation speed, and other factors. Therefore, you will have to experiment to get the
proper pump setting.
23.3 Tubing Size
Question: What is the correct tubing size for acid, base, antifoam and nutrient
feed for a fed-batch run?
Answer:
For vessels up to 5 liters, NBS part number TU202. This is Marprene
tubing with an inside dimension (ID) of 1.6 mm. It has an OD of 4.8mm (3/16"NOM)
and a wall thickness of 1.6mm. Larger tubing will be required for vessels over 5 liters.
It may also be necessary to use a connecting fitting to allow two different tubing sizes
to be used (in cases when the tubing size required for the pump and the size required
for the direct connection to the vessel differ).
NBS recommends silicon tubing for use with the pump heads provided as standard on
BioFlo fermentors. However, Marprene tubing may be used as well, as long as the
tubing size does not exceed 3/16” bore x 1/16” wall. Marprene tubing of this size or
smaller can be used with Watson-Marlow 101 pump heads under low pressure and
with clockwise rotation.