4 mL of a suspension containing the same quantity of cells
(adjusted to same OD600)
was mixed with 40 mL of sodium alginate (2%), and dripped
down on 40 mL calcium chloride (4%) in a 250 mL flask to form gel-entrapped cells.
For achieve CoQ10 production via a coupled process of conversion and extract
[7], a water-organic solvent and a two-phase conversion system, which contained
100 mL of acetate buffer (0.2 M, pH 4.6, containing 70 mg/L solanesol, as aqueous
phase) and 100 mL n-hexane (containing 35 mg/L PHB, as organic phase) were
devised. In the TPFBR, 160 mL of gel-entrapped cells was mixed with 200 mL of the
two-phase conversion system in which soybean oil was added to afford a final content
of 2%. After a predetermined period of conversion, 1 mL of the extract solvent
and aqueous phase were collected as the HPLC samples to detect the concentration
of CoQ10 and residual solanesol in organic phase and PHB in the aqueous phase.