2.6. Data analysis
As the fermentation went on, SLs was gradually accumulated in the broth
and once the O/S ratio reached at a certain range, the SLs sedimentation
was occurred. The average sedimentation rate was calculated by formula
(1). By fitting the height of SLs sedimentation was directly
proportional to the concentration of SLs, formula (2) was obtained. The
sedimentation rate formula related to SLs concentration could be derived
in (3).
\(\overset{\overline{}}{V}=\frac{H_{1}-H_{2}}{2t}\) (1)
\(\frac{H_{2}}{H_{1}}=0.0031\times c-0.0001\) (2)
\(\overset{\overline{}}{V}=\frac{H_{1}-H_{1}(0.0031\times c-0.0001)}{2t}\)(3)
Where \(\overset{\overline{}}{V}\) is the average sedimentation rate of
SLs in cm/s, H1 is the height of broth in the 10 mL
sedimentation tube in cm, H2 is the height of SLs
settled in the 10 mL sedimentation tube in cm, t is settling time in s,
c is SLs concentration in g/L.
Due to the consideration of working volume change by feeding, all the
presented data in Figures and Tables were normalized to the initial
volume. All experiments were performed in triplicate.