High-cell-density poly (3-hydroxybutyrate) production from sucrose using Burkholderia sacchari culture in airlift bioreactor
Author
Cruz Pradella, José Geraldo da
Keico Taciro, Marilda
Pataquiva Mateus, Alis Yovana
Institutions
Abstract
Burkholderia sacchari IPT 189 poly (3-hydroxybutyrate) (P3HB) production in airlift bioreactor were
investigated in batch and fed-batch culture using sucrose as carbon source. In batch experiments it
was observed that during the growth phase B. sacchari IPT 189 might display exponential growth even
at very low carbohydrate concentration, as long as NHþ
4 concentration was above 190 mg l1
. The onset
of accumulation phase took place when NHþ
4 concentration dropped below this value and continued as
long as carbohydrate was in excess, even with dissolved oxygen concentration at 0.0% of air saturation.
In the fed-batch experiments, nitrogen limitation was used to induce P3HB biosynthesis in a two-phase
process. In the first phase, an initial batch followed by a limited sucrose fed regime led to a growth with
low-P3HB-content (less than 13%) and up to 60 g l1 of biomass concentration in c.a. 25 h. In the second
phase, nitrogen concentration limitation induced P3HB accumulation up to 42%, raising the biomass concentration to c.a. 150 g l1
. Calculated parameters for the experiments were P3HB productivity = 1.7 g l1 h1 and P3HB yield factor from sucrose = 0.22 g g1