Pilot- and plant-scale culture
In a 300-l fermentor (KoBioTech), the first seed culture was
prepared in a 500-ml baffled flask in the same manner as
previously described. For the second seed culture, the first
seed of 50 ml was inoculated to a 7-l jar containing 5 l of
seed medium. Then, the culture broth was cultivated for
60 h at 30°C with 500 rpm and 1.0 vvm. The second seed
of 10 l, obtained from two 7-l jar fermentors, was transferred
to the 300-l fermentor containing 200 l of production
medium and followed by cultivation for 120 h at 34°C
with 260–480 rpm as the same velocity of the impeller tip
to a 7-l fermentor and 1.0 vvm.
In a 5,000-l fermentor (KoBioTech), the first and second
seed cultures were prepared in the same manner as described
previously. For the third seed culture, the second
seed of 5 l was added to a 300-l fermentor containing 100 l
of seed medium. Then, the culture broth was cultivated for
36 h at 30°C with 200 rpm and of 1.0 vvm. The third seed
was transferred to the 5,000-l fermentor containing 2,000 lof production medium and then cultivated for 120 h at 34°C
with 130–240 rpm as the same velocity of the impeller tip
to a 7-l fermentor and 1.0 vvm.
Determination of impeller tip velocity as a scale-up
parameter
To scale up from the laboratory scale (7-l jar fermentor) to
pilot (300 l) and plant (5,000 l) scales, the impeller tip
velocity (Vtip) was used as a scale-up parameter, and Vtip
was calculated by following equation (Wang and Cooney
1997): Vtip=2π N Di, where Vtip=impeller tip speed, N=
stirrer speed, and Di=impeller diameter. Diameters of
laboratory-, pilot-, and plant-scale impellors are 8, 15, and
30 cm, respectively.
đang được dịch, vui lòng đợi..
