EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 18

PID controlled Constant RQ Fermentation of Pichia pastoris in the DASbox® Mini Bioreactor System
Optical density measurements
We measured optical density using an Eppendorf
BioPhotometer D30 at a wavelength of 600 nm.
Samples were taken regularly during the fermentation.
To achieve an appropriate measurement in the
linear range between 0.2 and 0.8 the samples were
diluted appropriately.
Results
We ran P. pastoris fed-batch fermentation two times at
30 °C, pH 5.0 and a DO level of 30 % using the DASbox
Mini Bioreactor fermentation system for microbial
applications. In one set up, we started the feed automatically
by implementing a DO-spike triggered feed
started by a script. In the other set up, we successfully
implemented a constant RQ-controlled feeding
strategy. Throughout the fermentation, we took
intermitted samples for optical density measurements
to evaluate the growth of the cultures.
Figure 2: Scheme of the DO-cascade built in DASware
Control 5 professional. First, the stirrer speed is increased
(red curve) followed by the gas flow (black curve) and
finally oxygen is enriched (blue curve).
DO-Spike based feeding
As described earlier the DO-spike based feeding is
started once the value of dissolved oxygen raises
from 30 % to above 38 % which is the case after 39 h
inoculation time. Before the DO spike, we observed a
sharp drop of RQ value from 1.3 to 0.6 at 25 h inoculation
time, followed by a stabilized RQ value at
around 0.8 (Figure 3).
Figure 3: For the DO-spike triggered feeding the course
of DO % and RQ is shown over the inoculation time [h].
After 39 h a sharp DO-spike is visible.
18 | GENengnews.com
https://www.genengnews.com/ http://www.GENengnews.com

EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency

Table of Contents for the Digital Edition of EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency

Contents
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 1
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 2
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - Contents
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 4
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 5
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 6
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 7
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 8
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 9
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 10
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 11
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 12
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 13
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 14
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 15
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 16
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 17
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 18
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 19
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 20
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 21
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 22
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 23
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 24
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 25
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 26
EPPENDORF_Nov2021_UpstreamBioprocessingImprovingEfficiency - 27
https://www.nxtbookmedia.com