X. Kang et al., Effect of air flow rate on scleroglucan synthesis by Sclerotium glucanicumin an airlift bioreactor with an internal loop, BIOPROC ENG, 23(1), 2000, pp. 69-74
The effect of air flow rate upon scleroglucan production in batch cultures
of S. glucanicum NRRL 3006 cultivated in airlift reactor with internal loop
was studied using air flow rates from 0.25 m(3)/h to 1.00 m(3)/h. Biomass
formation was favoured at high air flow rates (with maximum biomass at 0.75
m(3)/h), whilst scleroglucan synthesis was highest at relatively low air f
low rates (maximal at 0.40 m(3)/h). S. glucanicurn had a maximum specific g
rowth rate of 0.018 h(-1) at 0.75 m(3)/h.
The values of the key process optimisation parameters (scleroglucan yield,
productivity and specific productivity) were all maximal at 0.4 m(3)/h. Sin
ce achievement of an adequate cell mass is essential for subsequent biopoly
mer synthesis, a bi-staged process was developed. In the first phase biomas
s formation was maximised by a high air flow rate of 0.75 m(3)/h, while in
the second phase a lower air flow rate of 0.40 m(3)/h was used to stimulate
biopolymer synthesis and minimise operational costs.