(g)

Reactors need to be equipped with immersion tubes

adjusted to the desired volume and controlled via a

peristaltic pump.

(h)

Each

bioreactor

requires

a

suitable

PI-controller

connected to a peristaltic pump to control the pH value.

(i)

All process parameters applied during cultivation need to

be logged. We recommend to use a process control system

to alter diverse set-points.

3. Each reactor system needs to be equipped with at least four

pumps:

(a)

Pump for feeding.

(b)

Pump

for

transferring/harvesting

cultivation

broth

depending on the reactor.

(c)

Pump for acid control.

(d)

Pump for base control.

4. All bioreactors need to be equipped with a pH probe (e.g.,

EasyFerm plus pH-sensor (Hamilton, Reno, NV, USA)). pH

probes need to be calibrated within a pH range of 4.01–7. pH

needs to be controlled for acidic deviations with 12.5%

NH4OH solution. If alkaline process deviations occur, pH

can be adjusted with 5% H3PO4.

Table 1

Composition of the defined medium according to DeLisa et al., which

is used for all performed cultivations [42]. Stock solutions for trace

elements are sterilized separately. All DeLisa medium components can

be sterilized together at 121 ˚C (see Note 1)

DeLisa medium

Final conc. (g/L)

Glycerol

Adjust to desired amount

KH2PO4

13.30

(NH4)2HPO4

4.00

Citric acid

1.70

Stock solutions

Final conc. (g/L)

MgSO4 · 7 H2O

1.20

Fe(III) citrate

0.1000

EDTA

0.0084

Zn(CH3COO)2 ·2 H2O

0.0130

CoCl2 · 6 H2O

0.0025

MnCl2 · 4 H2O

0.0150

CuCl2 · 2 H2O

0.0012

H3BO3

0.0030

Na2MoO4 · 2 H2O

0.0025

Thiamine HCl

0.0045

226

Julian Kopp and Oliver Spadiut