2.3
Growth Media
Prepare the Luria-Bertani (LB) growth media in broth and agar
forms for E. coli with the following components for 1 L: 10 g
tryptone, 10 g NaCl, 5 g yeast extract and distilled water. Add
agar agar (2%) with these components for agar media (see Note 3).
2.4
Spectro-
photometer
Use in following the cell concentration of E. coli at the wavelength
of 600 nm.
2.5
Chronometer
Measure the time and also obtain the DO concentration values
corresponding to those times.
3
Methods
3.1
Installation of the
Bioreactor
1. Use the orifice shape of sparger which is responsible in entering
of air bubbles into the bioreactor through air pump (see
Note 4).
2. Locate the Rushton turbine port in the STR (see Note 5).
3. Install the sampling port, the temperature detector and polar-
ographic type of DO probe inside the bioreactor.
4. Autoclave the bioreactor with all its parts placed inside for
sterilization of 20 min in 121 C (see Note 6).
3.2
Preparation of
the Growth Media
1. Prepare agar medium for sustaining the stock culture in petri
dishes or slant tubes. Weigh the components of tryptone, NaCl
and yeast agar plus agar agar according to required volumes and
mix them in the distilled water. Boiled the solution for
homogenization.
2. Prepare the components of broth media for scale up from agar
petri dishes to end inoculation volume of bioreactor. Start with
amounts of 5 mL of tubes and keep going with 10, 20 and
40 mL of volumes, respectively. Weigh the all components
except agar agar and mix them in the distilled water in the
required quantities (see Note 7).
3. Prepare separately the growth medium for bioreactor in 2 L of
volume.
4. Measure the pH values of growth media and adjust the pH to
range between 7.5 and 8 (see Note 8).
5. Autoclave the all growth media and equipment for sterilization
of 20 min in 121 C.
6. For agar medium: Shortly after sterilization, pour the broth
medium in aseptic conditions into sterile petri dishes/tubes
while at medium temperature of averagely 60 C and allow it
to solidify by cooling.
20
Aysegul Inam et al.