bioreactor studies of heterologous protein production by ...

3.6. Experimental Error and Reproducibiüty
in this research, the main fermentation variables were concentrations of glucose. cell,
ethanol and glucoamylase as weil as Mon of plasrnid-bearing ceils. They were
rneasured via the methods described in chapter 3. AU the measunmen$ were in triplicate
and the mean values were used (outlier points were deleted). Maximum variance in
rneasurements of glucose. ceU mass, ethanol and glucoarnylase did not exceed +/- 10% of
the average rneasured value. Relatively larger deviation occuned in measuring the
fraction of plamid-bearing ceils by plate count method. Maximum deviation associated
with measurements of fraction of plasmid-bearing celis could be as large as +/- 15% of the
reported values. Based on +/- 10% experimentd enor, gencrally only 2 sipificant
figures wm warranted. Howeva, in some cases more than 2 signifiant figures were
taken in the thesis because the data were generated by cornputer.
Most of the experirnenu reponed in the pmious chapters were performed twice
to three hes in order to check reproducibility. Typical reproducibiüty checks in batch
suspension fermentation, continuous suspension fermentation, continuous and repeated-
batch fermentations with the irnrnobiüled cells arc shown in Figure B. 1. B.2. B.3 and B.4
respectively. These figures show good agreement between wo experimental runs in tem
of trends as weil as values. Considering the measurernent variance disussed in the
previous section. good reproducibüity may be generalised to all the experimental data
obtained in this research Furthermore, the conclusions in rhis study were made based on
the results fiom different bioreactor operations or different strains. For example, by ushg